A first pass over freeglut_menu.c to bring it in line with the rest of

A first pass over freeglut_menu.c to bring it in line with the rest of
freeglut's style.  Mostly re-indenting and splitting long lines.
For those that may be concerned: No, I didn't do any more arrangments
of the form (CONST == a) rather than (a == CONST).  (^&

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@325 7f0cb862-5218-0410-a997-914c9d46530a