Upgrade Java buildpack dependencies to latest versions
Additional Java buildpack dependencies

OpenJDK lucid and precise 1.7.0_51, auto-reconfiguration 0.8.4, and play-jpa-plugin 0.8.4.

The OpenJDK upgrade is crucial as it fixes a number of serious security bugs.
Merge pull request #264 from glyn/master

Upgrade Java buildpack dependencies to latest versions