Add `Distance.raw_distance`, to compliment `max_distance`.
Exclude zero value penalties from `Distance.sorted`.
Group preferred media patterns, in case they contain "|" to keep them separate from the number of media.
Add `ignored` setting. Don't show matches with specified penalties applied, e.g. missing tracks or unmatched tracks.

If you know you never want these, they can clutter up the interface
especially now that we have multiple data sources.
Code style. Use "_" when expanding variables we don't need.
Colour benign track index changes in light gray, consistent with non-penalty supplementary information.
Colorise no-penalty text differences in a secondary colour, light grey.
Don't bypass candidate selection in timid mode. Always show all candidates.

Saves paranoid and interested users from having to either force all max
recommendations to none or constantly go back to candidate selection
from a recommendation to see if there is another slightly less similar
but more preferred (by the user) candidate.
rename "section" markup
item templates now expand all fields

A user noticed that $id wasn't being expanded. There's no good reason for
that.
Look at track penalties as well when downgrading recommendations for albums.
Improve preferred media/country and original year distance calculation.

Check only preferred media/country, if specified. Don't apply penalty
for preferred AND tagged mismatch.

Assume original year is 1889 (first gramophone discs) when we don't
know the original year.

Allow single values to be specified in configuration, instead of
requiring a list (e.g. use `as_str_seq()`).
Fix `add_priority()` calculation.

We were incorrectly adding 1 to the length of options to avoid a divide
by zero, when we should instead default the length to 1. Otherwise we
skew the penalty towards zero.
Fix unicode bug in Beatport plugin
possibly fix error for some Mutagen exceptions
handle FLACVorbisError exceptions from Mutagen
mediafile: pass through base IOErrors

This also tries to be a bit more thorough about capturing all the
Mutagen-originated exceptions.
fix MediaFile exception test
Merge pull request #301 from jbaiter/beatport

Plugin for Beatport Metadata in Autotagger
changelog/doc links for Beatport plugin (#301)