This was a vestige from when we used to need the unittest2 library for pre-2.7
compatibility. Now that we require Python 2.7, we aren't using that library
and this indirection wasn't doing any good.
This reverts commit 9c41c39913.
That commit used byte strings for the `if __name__ == '__main__'` pattern,
which was necessary when we were doing unicode_literals. But it is wrong on
Python 3, and now that we're liberated from unicode_literals, we need to go
back to native strings for this comparison.
Include import of __future__ features division, absolute_imports and
print_function everywhere. Don't add unicode_literals yet for it is
harder to convert.
Goal is smoothing the transition to python 3.
There was a bug in the find_feat_part function that would cause it to
fail if the album artist was the second part of the featured string.
For example, if the Artist field was Alice & Bob, and the Album Artist
field was Bob it would return None due to the order.
This fixes that and adds test cases to ensure it doesn't return.
This removes the code that extracts the featured artist from the
original artist field from the ft_in_title function and puts it into its
own.
It also adds a custom ArtistNotFoundException that find_feat_part will
throw if the album artist is not in the artist field.
This allows us to easily test the results of finding a featured artist
in the artist sting, and thus adds tests for the usual test cases that
the split_on_feat gets tested for.
