Additonal changes for Help Dialog: Add help for each 'wb_command' operation. ...

Additonal changes for Help Dialog: Add help for each 'wb_command' operation.  Use a Tree Widget (hierarchy) for the help topics.  Added deletion of CommandOperationManager to wb_view.  Had to create some 'dummy OSMesa' functions for linking to the GUI.  If the real OSMesa library was linked by the GUI, it totally screwed up the GUIs OpenGL.