2015.11

Mainly maintenance, but added ESRI layer and Mapquest API key for reverse geocoding.

API POST / PUT separation

This release introduces strict separation of POST for creating tasks / challenges, and PUT for updating existing ones.

New metrics model, speed optimizations

Merge pull request #278 from mvexel/master

Rework of stats store and endpoints

Revamped Stats Endpoints

Reworked stats API.

Adding local area support + various bug fixes

Merge pull request #253 from mvexel/master

user selection of preferred editing area + required backend changes