Adding a separate storage engine for Store definitions. Updating MetadataStore to use both innerstore along with this new storage engine
Modified metadata store to get/put/add/delete individual stores instead of the entire stores.xml. Also modified Admin service accordingly
Initializing store definition manager in the test constructor as well - which does not read the config from a directory
De-duping entries while creating stores.xml and fixed the version assignment
Fixing a bug where a put on stores.xml should atomically replace all the existing stores state