Fix colored_address when obj hasn't pings yet.

Ping.get_state(obj) raises uncatched exception
masked by admin, that shows '(None)'. Updated
exception to DoesNotExists as django 1.6 migration
Fix get_modeladmin: now import admin module works!
Add management address API member to slivers (#450)
Merge branch 'feature450' (#450)
Forbid change set_state in a PUT operation (#490)
Fix island refactor #264 postupgrade operation.
Released version 0.10.7
Refactor mgmtnetworks (decouple from tinc) (#157)
Merge TincServer and TincClient into TincHost (#157)

* remove TincServer.is_active
* remove TincServer and TincClient
* TincHost is no longer abstract
* change relationship TincAddress 1..n 1 TincServer by TincAddress 0..n 1 TincHost
* merge tinc_server and tinc_client backends and members into just tinc
Move tinc files out of mgmtnetworks folder (#157)

* Update menu
* Update INSTALLED_APPS
* Refactor communitynetworks app
* Decouple mgmtnetworks from tinc (remove monkey patching hooks)
Fix auto-id problem when migrating backwards (#157)
Avoid circular imports problems (#157)
Create mgmtnetworks/migrations/__init__.py (#157)
Added datamigration for generating mgmt_net for existing objects (#157)
Fix API serializers (#157)

* Make /mgmt_net writable
* Mark /tinc and /cn as optional
Fix pings hooks into mgmtnetworks app (#157)
Fix tinc autoconfig functions (#157)
REST API /tinc member writable (#157)
TincHost pubkey not null, check if tinc provided when needed (#157)
Update tinc.Host according to the specs (#272)

* Mark Host.description as optional
* Define a HostCreation serializer and set owner as request.user