Implement stupid-simple JSON persistence

Gson is one badass library. I tried ActiveAndroid, but it is way behind
the magic of Gson's reflection or whatever it does to serialize stuff.

Hopefully the schema won't change drastically, cause I don't really want
to mess with migrations.
Use Holo dark theme by default

dark as my soul
retract Xtend -> plain java

was 2alpha4me. Using Lombok for sugar now.

Still need to test on device, and make sure things are private and
stuff. Good 'ol java.
Fix java conversion issues

and cleanup code
Implement basic share action intent

The image it produces is stupid though. will improve later.
Merge branch 'retract'