Default config file in working directory

[evur]

Inspiration

When using beets to manage the current working directory with a custom config, beets must be invoked like this at the moment:
BEETSDIR=. beet -c/--config {config file} {command}
For example:
BEETSDIR=. beet -c beets.yaml ls

Suggestion

The suggestion is to do the following things if a beets.yaml exists in the cwd:

• Set the config directory (BEETSDIR) to the cwd.
• Ignore the user config and use beets.yaml instead.

This should replicate the behavior of the before mentioned command.

Note: beets.yaml is just my first idea. This obviously doesn't need to be the final name.

Further ideas

• The default library path could be changed to something more specific like beets.db when a beets.yaml exists.

Conclusion

With this feature implemented, it would be possible to just call beet without any arguments or changing environment variables in this situation.