Represent tips as (tip, signature) tuples
Tests for get signature
Sanely marshall and store signatures
Test deals with untrusted signatures
Nuke a ton of dead user code
Load crypto adaptor on station
Send signatures with responses in airship
Bootstrap stations from environment
Implement lookup of crypto adaptors
Fixup mistake in file.read() semantics
Fix public key lookup
Script to sign grefs
Squashed commit of the following:

commit 728df4ad4df0bd097d925174f10188b7edbf4fc0
Author: richo <richo@psych0tik.net>
Date:   Wed Mar 27 09:14:06 2013 +1100

    WIP! include hashes on events for signature validation

commit 01c69b6103e90d80dd861aefd2d9b2e102cdff50
Author: richo <richo@psych0tik.net>
Date:   Wed Mar 27 03:56:27 2013 +1100

    Light up hashes in response to signature data
Show signature status in the UI
Send signature status to the client properly
Use good/bad colours from bootstrap