Updating Java build detection to detect either 1.6.0_51-b11-457-11M4508 (on 10.6.x) or 10.8.x: 1.6.0_51-b11-456-11M4508 (10.7 / 10.8)

This Casper Extension Attribute determines if either of the the
following Java builds are installed:

10.6.x: 1.6.0_51-b11-457-11M4508
10.7.x - 10.8.x: 1.6.0_51-b11-456-11M4508