Fixed keys in JSON user output and made it so that uid and display name are always either both present or both absent.
Refactoring to fully remove changeset cache from main.
Merge remote-tracking branch 'origin/master' into changeset_cache_refactor
Merge commit '5f7471dc4f3b3e6c7855bee185be5428bea84f5f' into gsoc13

Conflicts:
	src/main.cpp