Added friendly names to builders

- This commit allows us to start phasing over to a static ID, while having the ability to change what the user sees from the front end without losing old logs
- To add a friendly name to a builder just supply the friendly_name field, if this is missing the name will be used for this instead
- Fixed a minor issue in the logs page where we were creating the back button with JS rather than with Python
Merge branch 'friendlyBuilderName' into jsonImprovements
Added friendly names for builders to the JSON
Merge branch 'jsonImprovements' into autobahn_v1

Conflicts:
	master/buildbot/status/web/builder.py
	master/buildbot/status/web/buildqueue.py
	master/buildbot/status/web/slaves.py
	master/buildbot/status/web/templates/builders.html
Switched names for builders to friendly names