[7u4] Review request for CR 7124286: [macosx] Option modifier should work like AltGr as in Apple jdk 6

[Leonid Romanov]

Hi,
Please review a fix for for http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7124286
webrev: http://cr.openjdk.java.net/~leonidr/7124286/webrev.00/

Since this fix modifies shared code, I tried to keep as much of original code as possible. Also, isPrintableCharacterModifiersMask() might be not the best name possible: the reason I used it is because I couldn't come with better name.

Thanks,
Leonid.