Fixed compiler warning from spray-json
Fixed problem where Spray's header parser was rejecting content produced by Riak

Spray's header parser follows the Http spec strictly and it says that all "ETag" header values should be quoted. Unfortunately Riak doesn't quote their ETags so I had to find a workaround for that.
Upgraded to Sbt 0.13.5 and the latest versions of all libraries
Removed the need for custom SprayJsonSupport since the problem got fixed in Spray a long time ago
Migrated to using sbt-scoverage instead of scct and/or jacoco
Turned on the Scalariform plugin and reformatted the entire codebase