fromfilename: fix #460: crash w/ no capture groups
fix typo in BytesQuery
fix mpdstats plugin after query restructuring

BytesQuery does not handle unicode strings correctly at the moment
and PathQuery seems like a reasonable query to use.
Merge pull request #516 from kljohann/typo

fix typo in BytesQuery
fix #517: BytesQuery accepts unicode strings
Merge pull request #515 from kljohann/mpdstats

fix mpdstats plugin after query restructuring
tiny option-choosing fixes for #518

* 'L' check needs to be lower-case
* letter for 'More candidates' is M, not C
a bit more docs, changelog for #518
Add empty test audio files
Rewrite mediafile tests
Extract assertTags method
Simplify MediaField descriptor
Refactor get/set into StorageStyle
Add MP3 StorageStyle class
Add serialize method for StorageStyle
Add unpack method for storage style
Refactor MP4 tag decode
Refactor StorageStyle packing
Tests include all file formats
Add UFID storage style