added .metadata to .gitignore
minor fixes to a few project warnings
[issue 70] Added support for generating Gson compatible types. Changes include: Added Gson dependency. Minor refactor of Annotator interface in order to add GsonAnnotator. Extending an AbstractAnnotator makes creating implementations a tad easier. GsonAnnotator logic only adds SerializedName annotation to fields when it's necessary.
Merge pull request #4 from gmale/issue70/addgsonsupport

issue70/addgsonsupport