- Change min API to 7 (2.1), to make things a little easier.
  This covers 95% of active devices and older ones are likely
  too crappy to run I2P anyway.

- Beginnings of a BroadcastReceiver
- ant target for signing key
- Status thread
- Status in status bar for now

Next step: Update the scripts and docs to point to
../i2p.i2p/ for everything.

  - Move the classes around
  - Split into Activity and Service
  - Add status bar notification
  - More config changes