Release/0.7.1

Patches absolutely needed to get [rww-play](https://github.com/read-write-web/rww-play) to work. 

Will be presented it as an example of an application using banana-rdf at [Scala-eXchange](https://skillsmatter.com/conferences/1948-scala-exchange-2014#program) early December 2014.

Need to have this in  issue #190 "Release 0.7.1"