Sync using Myelin

Todo:

* [x] Reduce Blinker handlers in Synapse/ElectricalSynapse to one "local model changed"-handler
* [x] Remove old handlers and update calls from web_ui
* [x] Rewrite Starmap class to directly use Star IDs instead of Orb objects
* [x] Add Persona.profile (starmap)
* [x] Add new Stars to Persona.profile
* [x] Transmit Persona.profile to new contacts
* [x] Request objects from received Persona profiles
* [x] Add documentation