Changed CreateNotify (in X11 ONLY) to act like a ConfigureNotify event.

Changed CreateNotify (in X11 ONLY) to act like a ConfigureNotify event.

This is done so that subwindows on X11 will get "resize" events when
they are created.  Old GLUT did this---presumably by design in order
to ensure that (a) All windows get notified of their size as soon as
the window exists, and (b) probably more importantly, so that windows
and sub-windows behave as much alike as possible.  I believe that GLUT
was right to do this, and I believe that compatibility requires this
(I have a sample program that breaks in freeglut but not GLUT without
this fix).

I did not touch the Microsoft side, because I don't know what their
OS does---nor if old GLUT was historically system-dependant about this.

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@217 7f0cb862-5218-0410-a997-914c9d46530a