syncbase: add hook to get service and DB stores (needed by sync)

Also moves internal interfaces to a separate package, hopefully
making the code structure easier to grok.

Change-Id: I449bfa9ed184334118dd28b2695d9792c7f43f56
14 files changed
tree: 98bf59f639237c8b39fb7d880b1cf9d6fd0e109f
  1. services/