JERSEY-2136: Jersey 2 doesn't work with Google Application Engine.

 - Fix in JdkVersion (using custom System property GAE sets).
 - Added integration test (development environment).
 - Manually tested on production (production environment).
 - Using GAE 1.8.4 - latest version compatible with JDK6 and Maven 3.1.1.

Change-Id: I0bdd0c46b615a30db1362d2d00b2694a55ecfce9
Merge "JERSEY-2136: Jersey 2 doesn't work with Google Application Engine."