Change download_coverart{front,back} to use download_coverart

Signed-off-by: Wieland Hoffmann <themineo@gmail.com>
CAA documentation

Signed-off-by: Wieland Hoffmann <themineo@gmail.com>
caa: Pass through 404 errors

Signed-off-by: Wieland Hoffmann <themineo@gmail.com>
caa: Highlight `releaseid` in docstrings

Signed-off-by: Wieland Hoffmann <themineo@gmail.com>
Further improve the CAA documentation

This makes use of Sphinx' python domain in several methods

Signed-off-by: Wieland Hoffmann <themineo@gmail.com>
Change 'coverart' into 'cover art'

because those are two words

Signed-off-by: Wieland Hoffmann <themineo@gmail.com>
Add release group methods to caa.py

Signed-off-by: Wieland Hoffmann <themineo@gmail.com>
fixup! Add release group methods to caa.py

Signed-off-by: Wieland Hoffmann <themineo@gmail.com>
Add a paragraph about the CAA to the usage docs

Signed-off-by: Wieland Hoffmann <themineo@gmail.com>