Make Rest proxy stuff a bit more modular and thus testable. Add RestInvocationHandlerTest.
Merge pull request #20 from mmazi/restproxy-test

Made Rest proxy stuff more modular and testable. Added test.
cleanup
Added some javadocs. Renamed a method.
Merge remote-tracking branch 'upstream/develop' into develop
Merge branch 'develop' into mtgox-jaxrs-withdraw
Support null parameter values (by ignoring them).