import renderd-client patch
Merge branch 'master' into renderd-client

Conflicts:
	mapproxy/cache/tile.py
	mapproxy/config/loader.py
update client.renderd for http renderd server
enable locking for renderd tile requests
reenable logging of renderd requests
better support for mapnik 2

- cache mapnik.Map objects when using inside renderd
- deprecate use_mapnik2 option
Merge branch 'master' into renderd-client
add system test for renderd client
refactored RenderdTileCreator
add sqlite cache with db file for each level
add remove_all and remove/refresh_before.seconds options to seeding
remove tiles in sqlite cache by timestamp
add more tests for sqlite cache
fixed locking of mbtiles
fixed refresh/remove_before.mtime tests
use shutil.rmtree for remove_all for file caches
add more tests for sqlite cache seeding and cleanup.remove_all
document remove_all option
document sqlite cache
Merge branch 'master' into sqlite-cache