WB-860 NIFTI Volume Time Series Issues: Volume File was not overriding getMapIntervalStartAndStep() to report the time step and this has been fixed so that time-series line charts display correctly.  For any previously created line-series charts, one must reselect the brainordinate to correct the chart.

WB-860 NIFTI Volume Timeseries Issues: VolumeFile was always reporting NIFTI_UNITS_UNKNOWN as it failed to override CaretMappableDataFile::getMapIntervalUnits().  VolumeFile now overrides getMapIntervalUnits() and it returns NIFTI_UNITS_SEC if the time dimension is greater than one and NiftiHeader::getTimeStep() is greater than zero.

 For the experimental texture volume drawing, more enhancements including addition of a developer flag to smooth voxel drawing (remove aliasing artifacts) and use of the GLM library to replace some GLU functions.

Added OpenGL Mathematics (GLM) library that will be used in future OpenGL code.  From the GLM description: "a header-only C++ mathematics library for graphics software based on the OpenGL Shading Language (GLSL) specifications. An extension system provides extended capabilities such as matrix transformations and quaternions."  It also contains functions that replace some of the GLU functions and some that replace OpenGL functions that are in the Fixed Pipeline OpenGL  API but not in the Programmable Pipeline OpenGL.  On Linux, the CMakeLists.txt file uses the PKG_CHECK_MODULES command to look for a GLM package and, if found, is used instead of the GLM headers in the Workbench source code.

For the experimental texture volume drawing, detect a volume that has dimensions too large and avoid creating a texture and then log a warning.

For the experimental texture volume drawing, fixed drawing of volumes with 'other' orientations such as SRP.

Added display of sform and coordinates of corner voxels for volume files in "wb_command -file-information".

For the experimental texture volume drawing, fixed drawing in all view and removed some unused code.

For the experimental texture volume drawing, added identification and some fixes for ALL view slices.

Coloring code for CIFTI volume slice viewing was incorrectly setting the alpha value.  The RGBA colors are unsigned bytes but the alpha value was treated as a float.   It has been corrected to assign the byte alpha value to the voxel and not multiply the alpha by 255 (incorrectly converting float to byte).  This resulted in a numerical overflow and and incorrect alpha value.

Fix in WuQSpinBox: Need to avoid calling parent's keyPressEvent() when the return key is processed in WuQSpinBox.

WB-830 Line Series Yoked Within File Even When Yoking Off: Updated Cifti Row Spin Box so that if row is identified if the user presses the return key.

WB-830 Line Series Yoked Within File Even When Yoking Off: Updated Identify Brainordinate Dialog so that it supports a CiftiScalarDataSeries file for row selection.  This allows the user to choose a row that is loaded into a line chart for the file.

Disabled filtering of files listed in chart overlays for scalar data series files as the requirement is not well defined and we have not considered problems that may result.

The line chart history widget (part of overlay and map settings dialog)  listed the name of the file containing the line charts.  This filename has been removed since the filename is listed at the top of the overlay and map settings dialog.

WB-830 Line Series Yoked Within File: Updated to only hide a scalar data series file if the overlay is disabled

WB-830 Line Series Yoked Within File: If a scalar data series file is selected in an enabled overlay, do not show the file in any lower level overlays.

WB-830 Line Series Yoked Within File: Add arrows to line chart history items so that they the line chart history can be re-ordered.

Implement WB-713 Window Background Color: Added window foreground and background colors that are set on Preferences.  If an older scene is loaded that does not contain window colors, the surface colors are used (previous functionality used surface color for background).

Additional correction to prevent duplicate lines series charts from being loaded when yoking was active.  Fixed memory leak caused by failure to delete the duplicate line charts.

Fix two line chart (scalar data-series) bugs: (1) When yoked, a duplicate line series chart was being loaded and displayed in the history list; (2) Row and column index in history list has been updated to start at one and thus matches the row and column index in the chart overlays.

Map yoking combo boxes were set to a fixed size on Mac.  On newer Qt (5.12.0), these combo boxes were too small.  This logic was removed and QComboBox::setSizeAdjustPolicyt() is used to size the combo boxes to their content.

Fix charting bug with scalar data-series files.  If the user clicked in a matrix view, line charts for the file were not updating to show the row's data.

This change only affects the usage of QOpenGLWidget which is used with Qt 5.12.0 on John's Mac.  All build systems use QGLWidget with Qt 5.7.x.   Anyway, there is a bug in QOpenGLWidget::repaint() as it does not function as described in the Qt documentation.  It is supposed to repaint the graphics (call paintGL()), before returning.  However, it does not and functions like QOpenGLWidget::update() and returns with the graphics being updated later by Qt.  There are two Qt bug reports for this (QT-BUG-74404 and QTBUG-53107).  A previous work-around made a call to QApplication::processEvents() after the call to repaint() and it appeared to fix the problem.  However, annotation dragging was found to be unusable (annotations kept moving after release of the mouse and did not follow the mouse) due to processEvents() allowing mouse event while still updating graphics.  Now, the call to processEvents() has been replaced with a call to grabFrameBuffer().  This captures an image and I assume it waits until the graphics have updated before capturing the image.  This fixes the problem with annotation dragging.

Unfortunately, the previous commit for keeping the main window active does not function as desires on Linux.  It appears (on Linux) that the active window is always the top most window.  The functionality remains for Mac so that the Identification window is over the main window after an ID but the main window retains mouse focus.  A difference between the main window on Linux is that if the main window is not active, clicking any control (slice spin box), makes the window active.  On Mac it is different as the user must click the titlebar to make the window active (clicking a control such as slice spin box does not activate the window).

Previous commit for keeping main window active after identification operation was obscuring the identification window if it was behind the main window.  This fix (at least on Mac) keeps the main window as the active window (mouse focus) but keeps identification window visible over the main window.

When an identification operation was performed, the identification window became the top window and the keyboard focus was moved to the identification window.  This has been changed so that the keyboard focus no longer is transferred to the identification window and the keyboard focus remains with the main window.

Code that processed mouse wheel (track pad is reported as mouse wheel event) was using an obsolete function, QWheelEvent::delete(), and it was replaced with QWheelEvent::pixelDelta() and QWheelEvent::angleDelta() as a fallback.  This seems to have fixed the sort oscillation that was noticed when trying to use the track pad on Macs.