should be using GetKeyState not GetAsyncKeyState to check for modifier keys as we care which modifiers were active at the time of the key/mouse press we are processing

git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@1642 7f0cb862-5218-0410-a997-914c9d46530a
Merge branch 'svn/trunk'