Java Buildpack 2.1.2

This change updates the Java Buildpack to version 2.1.2.  Version
2.1.2 fixes a bug in Java Buildpack Auto-reconfiguration and adds
support for Ubuntu 14.04 (Trusty Tahr).

Both the online and offline buildpacks are updated as part of this
change.
Merge pull request #367 from nebhale/java-buildpack-2.1.2

Java Buildpack updated to 2.1.2