Added controls for matrix file loading by row/column and yoking, but no implementation yet.
Hide controls for matrix file loading by row/column and yoking since their implementation will be deferred.
Add a few more logging messages to get track time for each step in scene restoration.  Much time was used for restoring the user-interface so the user-interface update event is blocked during scene restoration and it has reduced scene loading time.
remove unused include file.
Added a few more logging messages to time the steps in reading a volume file (Steps include: Reading the data, processing extensions, process labels into a hierarchy, and coloring the voxels).
Fixed slowness bug in GroupAndNameHierarchyModel.  If a map names from a GIFTI Label, CIFTI Label, or Volume File was a zero length string, the GroupAndNameHierarchyModel for the file was being updated every time an overlay changed resulting in several seconds to change an overlay.
Bug Fix: Features Toolbox->Labels was not enabled when a Volume Label file was loaded.