Bump to 1.5.0
General dep upgrade:

* Upgrade to rack ~> 1.5.2
* Upgrade to rjack-jetty ~> 9.0.0 (>= 9.0.0.5/v20130308 release)
* Upgrade/narrow to rjack-slf4j ~> 1.7.2, -logback ~> 1.2 (dev)
* Upgrade to json ~> 1.7.7, rspec ~> 2.13.0 (dev)
Release date