OSIdentifier.isMacintosh() returns false using Oracle Java 1.7 on OSX

[rjenks]

Using FEST 1.2. Works in Apple's Java 1.6, but not Oracle's Java 1.7.

The issues is that this function depends on the system property "mrj.version" which is not set in Oracle's Java 1.7 for OSX. There is a Java bug on this issue, but it's not marked as fixed until Java 8.
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7149564

Because this function returns false, isOSX() also returns false.

I'm not sure what to suggest other than to simply have isMacintosh() and isOSX() simply depend on os.name equal to "OS X" for both checks.