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

Added functionality to update partial stores.xml. Added unit tests for the new functionality