Basic Authorization

[supernevi]

Is your feature request related to a problem? Please describe.
By now all API calls are open without any authorization. But usually you only want some applications allow access to your song repository, especially if your server is hosted in the cloud.

Describe the solution you'd like
Some authorization routines should be available. This can be done with Basic OAuth authorization. For this, the server should generate a client id and a secret and store this information in a local file since this can be reused after restarting the server. I don't think that any encryption is needed here (for now)