Bootstrap stations from environment

Conflicts:
	groundstation/station.py
Test station init
Add a notification type and a simple handler
Add tests for notification type
Stub implementation for handling new tips
Helper for converting on disk objects
Refactor to export object_root
--watch-fs flag to dump to network
Add a watcher and (awful) tests for it
install watchdog
I'll write my own FS wrapper. With blackjack. And hookers.

And also syncronous operations, like the FSM intended.
Nasty heuristic to dodge tempfiles on linux
Refactor around new fs_watcher api