feat(redis): added ability to specify a redis key prefix for all cache regions of dogpile that use redis backend

fix(mercurial): actually use assert_path instead of always initializing repo object. This makes it consistent with how things work on git and svn sides

fix(caches): actually obey wire cache flag on local method caching

caches: improve logging

deps: msgpack==1.1.0

fix(sqlalchemy): fixed deprecated methods for sqlalchemy

fix(tests): fixed more permissions tests

fix(tests): fixed few tests

fix(configs): fixed some config bad default setting

caches: allow force re-init of cache region for re-creating the cache