Unlock editing contexts disposed by the ERXRouteController

The ERXRouteController disposes the editing context at the end of the request handling. If the editing context is autoLocked during the request, at least one lock will remain open at disposal time (because of the coalesceAutoLocks property). This change unlocks the editing context before disposing it, avoiding inaccurate warnings when the tracing open locks option is enabled.
Merge pull request #593 from hprange/improveRestControllerCleanUp

Unlock editing contexts disposed by the ERXRouteController