Fix a couple of races in testing.
Addressbook style contact renaming in the GUI.
Based on https://github.com/burdges/pond/commit/d41c34c4f5396c22d754c2e6236dd8bcbe5126e9 and https://github.com/agl/pond/commit/2fa2722f1f0b80ef2cc6bd2c32cf3aac805a188c