Clean up of logging messages as described here

All logging now prefers the ' (single quote) over the " (double quote)

https://github.com/sampsyo/beets/wiki/Hacking
Merge branch 'master' of https://github.com/sampsyo/beets
flake8 cleanup

Cleanup after cleanup
Fix Travis errors

I was over zealous on the brackets for formatting
Oh the formatting
Just go back to basics
displayable_path clean up error
First commit towards a linking move_file().
Now reads config['import']['link'], style fix and default setting added.
Style fixes.
Failing to link a file now throws a FilesystemError.
Update genres-tree.yaml

Scraped https://en.wikipedia.org/wiki/List_of_popular_music_genres for the first time since @KraYmer did back in (apparently) October 2011. This should be much more useful now to those who have genre canonicalization enabled. Script is in public repo of mine :)
Alphabetize! Thanks @KraYmer
Update genres-tree.yaml
Change expected result for compatibility with updated genres-tree.yaml
Merge remote-tracking branch 'origin/patch-2' into patch-1
Correct busted encoding hopefully
Add support for re-importing added dates.

When re-importing, `item.added` and `album.added` will be preserved if
their path match what they are replacing.
Remove duplicate OrderedEnum and use utils instead

This is a leftover cleanup from c4e6f389.
Clean up of logging messages as described here

All logging now prefers the ' (single quote) over the " (double quote)

https://github.com/sampsyo/beets/wiki/Hacking