feat(registry): deis-cache for saving meta data

This improves the registry speed with remote stores and improves the developer UX

Fixes #1780, fixes #1794
Redis doesn't listen to SIGHUP (thats why there is no reload cmd) and nsenter means the configuration is gone after rescheduling. If confd is a pain, shouldn't we fix it instead of working around this issue?
Would https://github.com/kelseyhightower/confd/pull/85 help?