User can now drag widgets from the toolbox into the grid
or use the context menu to add them into the corresponding
cell. If no position is indicated, now children are added at the
first free cell.
- FL/Fl_Grid.H: header file
- src/Fl_Grid.cxx: implementation
- examples/grid-simple.cxx: simple example program
- test/cube.cxx: use Fl_Grid for layout
- test/grid_alignment.cxx: test cell alignment and other functions
- test/grid_buttons.cxx: demo program as discussed in fltk.general
- test/grid_login.cxx: like test/flex_login.cxx but with Fl_Grid
- test/flex_login.cxx: modified to match test/grid_login.cxx
