Updated all benchmarks to Play 2.3.6 and Scala 2.11.4.

Updated Ebean benchmarks to include missing tests as well as include HikariCP version.
Moved `/plaintext` tests from JPA/Ebean benchmarks to the `play2-java` benchmark as per https://github.com/TechEmpower/FrameworkBenchmarks/pull/1149#dis
Added BoneCP qualifier as per https://github.com/TechEmpower/FrameworkBenchmarks/pull/1149#discussion_r19584629 and changed names accordingly.
@richdougherty The database updates were running on the default thread pool whilst the selects were running on the `dbEc` context. To make things more consistent, I've moved the updates to run on this context as well.

Thoughts?