Backup / restore bug fix

Bug fixes for issues #13, #18, #23. Will complete filter API for 1.0.

Maven / gradle support

Reorganized the project to build with maven and test with gradle, resolves issue 11.
Renamed storm-apt.jar to storm-impl.jar to avoid confusion between api / apt.

storm-gen 0.97

Last release from https://code.google.com/p/storm-gen/