- moving to a new way of handling window changes (position, size, visibility)

- moving to a new way of handling window changes (position, size, visibility)
- we now use a work list and all actions queued up in that list get executed in the main loop, just before redraws are called
- simplified redrawing on windows, now no longer doing so in response to WM_PAINT message. This allows us to full control over when we draw
- now simplified use of state variables in X11 and andriod
- resize, reposition etc callback now processed thru notify checkers that call callback only if needed
- worklist also has an init work type which is executed once for every window, just before the window receives its first draw. This gets rid of hacks to call the reshape function once (that only worked for windows that are created before mainloop is entered)
- in init work processor we also check for presence of draw callback as not having one is an error following GLUT.
- some cleanup in general

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@1577 7f0cb862-5218-0410-a997-914c9d46530a