[7u4] Review request for 7154072 [macosx] swallowing key events

[Anton V. Tarasov]

Hello,

Please review a fix for 7154072.

webrev: http://cr.openjdk.java.net/~ant/7154072/webrev.1

A pointer to NSEvent was used to compare current and previous key events in order to skip repetitive 
ones. The pointer didn't retain the object and when a new key event object was allocated by the same 
address the events were considered equal. The latter was erroneously skipped.

A new regression test is provided as well.

Thanks,
Anton.