Slightly modified version of the second version submitted.
It reuses the resizing code for the mouse drag and does not turn on the overlay
if it has been toggled off. Also cleaned up some very hard to understand
code for handling FL_KEYBOARD.
Arrows move the selected widgets by 1 pixel
Shift moves the right+bottom edge of the selected region
Ctrl moves by the current grid step
Also typing the letter 'o' in a window is a shortcut to toggle the overlay
on and off.
git-svn-id: file:///fltk/svn/fltk/branches/branch-1.0@712 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
54a6bda767