Updated .gitignore
First ORMlite steps
Progress with ORM

* more unit tests (like for the DbStorage )
* implemented IStorage
Passing all unit tests using new DatabaseBackend
Progress
Fix hardcoded test server Uri
Refactor some files, seperate db layer a little more
Seperated OAuth stuff for different backends
Major overhaul and refactor, removed plaintext metadata backend

* Removed plaintext metadata backend (manifest, oauth). Instead, those
  are now written into a sqlite database file