Fixed some critical issues

fixes #370, #373, #368 due to refactoring the pynote.config
and pynote.init modules.

I have tested several possible states:
- noterc does not exist -> now it takes default values
- data dir or data files do not exist -> catch a FileNotFoundError
  in pynote.container

I have also tested pynote.init with all these states. I think now it
works well.

Signed-off-by: Stefan Tatschner <stefan@sevenbyte.org>
Removed a hint to git flow

Signed-off-by: Stefan Tatschner <stefan@sevenbyte.org>
Updated translations

Signed-off-by: Stefan Tatschner <stefan@sevenbyte.org>
Bumped version number

Signed-off-by: Stefan Tatschner <stefan@sevenbyte.org>
Updated changelog

Signed-off-by: Stefan Tatschner <stefan@sevenbyte.org>
Changed headline format of changelog

Signed-off-by: Stefan Tatschner <stefan@sevenbyte.org>
Typo

Signed-off-by: Stefan Tatschner <stefan@sevenbyte.org>