Reduce queries used to lookup config
Don't create tree for main map view

Was not used in templates and is very expensive process.
Cache JSON of tree
MapJSONGenerator.get_cache_key is not private
Updating Wormhole model invalidates cache
First shot at Map optimization
Build tree in python
Use foreign key variable instead of custom get

Allows us to use select_related to optimise code
Use select_related to reduce SQL
Only fetch interest systems once
select related wormholes initially
Use exists() to check if row exists

More efficient than calling count and then testing for >0
Merge branch 'develop' into buildTreeInPython
Merge remote-tracking branch 'parent/develop' into buildTreeInPython
Merge branch 'develop' into buildTreeInPython

Conflicts:
	evewspace/Map/utils.py
Merge pull request #54 from joshuablake/buildTreeInPython

Improve Map Performance