Merge pull request #62 from LostInBrittany/issue59

Issue #59 : Sending GStrings in EventBus

As the problem was sendi ng GStrings in EventBus, I've modified the Groovy EventBus to deal with GString, as done with Groovy Lists or Maps.

I've also added Unit Tests
Merge pull request #63 from LostInBrittany/issue59

Issue #59 : Adding normalize methods for GStrings inside list and maps
Following @nscavell advise for dealing with GStrings inside maps and lists.
Merge branch 'master' of github.com:vert-x/mod-lang-groovy