Bump Play Slick plugin to 0.8.0; misc other version bumps

* Play to 2.3.2
* Scala to 2.11.2 (but with comment about 2.10.4)
* webjars-play to 2.3.0
Merge pull request #1 from richdougherty/version-0.8.0

Bump Play Slick plugin to 0.8.0; misc other version bumps