Closes #36: ingestion of tiles optimizes for upload but causes caching problems for clients
Fixes #35

Squashed commit of the following:

commit d25ef6fc362e43237fab1cd7228ec258db3cf30a
Author: Olivier Yiptong <olivier@olivieryiptong.com>
Date:   Wed Nov 5 12:21:35 2014 -0500

    store images by sha1 hash / length combination instead of locale/tile_id for better client caching

commit d531bc7a3779978a10d49e917385c0da7652d720
Author: Olivier Yiptong <olivier@olivieryiptong.com>
Date:   Wed Nov 5 11:21:15 2014 -0500

    test_ingest.py: move misplaced tests in proper class
version bump to 1.0.14