Renamed Track.number to Track.ordinal
Simplified basic object retrieval

The logic for getting all objects of a certain type, or an object by slug or id
was abstracted away to the base Resource class.
Created allow_method decorator

It only checks for the ALLOW_DELETE config at the moment. Maybe would be useful
to globally prevent other methods like POST in the future.
Merge branch 'get_by'
Merge branch 'allowmethod'
Changed destination path for converted files

The converter won't pollute the directory where files are originally stored any
more. Now it creates a sub directory named after the file extension and stores
the new files there.
Bugfix: Excluded dirs were not being excluded
Implemented UploadHandler

This class will take care of storing uploaded files.
Added POST method for object creation
Merge branch 'exclude'
Merge branch 'post'
Users!

Added User resource and model.
Testing resources