- changed mBorderEdges to be heap allocated (only needed for collapsing border model)
- made the 8 boolean data members into bitfields
- changed mColumnWidths to be as small as necessary instead of defaulting its size to 100 elements
git-svn-id: svn://10.0.0.236/trunk@49748 18797224-902f-48f8-a5cc-f745e15eee43