Link to JIRA change log instead of local changelog.txt file
Prepared for JDK 1.9

Aiming for the JdkVersion class to support one generation ahead now, in order for the test suite to properly detect 1.7/1.8+ JVMs even when running against a JDK 1.9 preview at some point.
Upgraded to Jackson 1.9 (raising minimum to 1.8+) and 2.2