some cleanup, correctness in naming, correctness in type (those ATOM should be BOOL)

git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@1712 7f0cb862-5218-0410-a997-914c9d46530a
Tidy-up: config.h included via fg_internal.h no deep to duplicate.

git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@1713 7f0cb862-5218-0410-a997-914c9d46530a
more cleanup: config.h include never needed in demo

git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@1714 7f0cb862-5218-0410-a997-914c9d46530a
Merge remote-tracking branch 'svn/trunk' into git_master