Fixing freeglut's desire to initialize the spaceball every time a window is checked...

Fixing freeglut's desire to initialize the spaceball every time a window is checked.  Now it tries once the first time a spaceball function is called and after that if it fails it doesn't try any more.  This is per an e-mail from Diederick Niehorster vintage 6/8/11 at 3:17 AM, referring to feature request 3190319.

git-svn-id: svn+ssh://svn.code.sf.net/p/freeglut/code/trunk/freeglut/freeglut@928 7f0cb862-5218-0410-a997-914c9d46530a