[7u4] Request for approval for 7124337: [macosx] FileDialog fails to select multiple files

[Dmitry Cherepanov]

This is a request to push the following fix to jdk7u-dev:
CR: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7124337

Webrev: http://cr.openjdk.java.net/~dcherepanov/7124337/webrev.0

Technical review: 
http://mail.openjdk.java.net/pipermail/macosx-port-dev/2012-February/002917.html

Thanks,
Dmitry