Implement WB-633 : New requirements for updating of connectivity data: (1) A...

Implement WB-633 : New requirements for updating of connectivity data: (1) A second checkbox that enables dynamic connectivity has been added to Overlay Toolbox --> Connectivity.  Dynamic connectivity files are only available in the Overlay --> Layers section if this checkbox is checked; (2) Checkbox labeled "On" has been changed to "Load" on Overlay --> Toolbox; (3) A preference has been added for enabling dynamic connectivity data from data-series file on Preferences Misc tab; (4) Old scenes will default to dynamic connectivity on.  Name of dynamic connectivity file in Overlay --> Layers and Overlay --> Connectivity is now prefixed with "dynconn".