Fixing the previous commit so we don't have a circular include. Under the new regime...

Fixing the previous commit so we don't have a circular include.  Under the new regime, the "freeglut_internal_mswin.h(platform).h" file will have only platform-specific definitions in it and will be included at the top of "freeglut_internal.h".

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@1010 7f0cb862-5218-0410-a997-914c9d46530a