New Lyrics API

We've been working recently on new API for Lyrics Wikia. Yesterday, the API passed QA and we want to merge this changes to `dev` branch. Unfortunately, we're not done with scrapers part but it won't hurt us to merge the files which were already used for the first, initial scraping and feeding our `lyrics-api` core in Solr (`maintenance/wikia/lyrics/` directory).

The code has been internally reviewed but feel free to leave your comments @federico-lox @idradm @owend @pchojnacki @Szumo @wsuchy Please focus mostly on files in `extensions/wikia/LyricsApi/` extensions since it was fully code reviewed, QA'ed and this is the part we want to release next week :)

After merging this changes we should merge two more pull requests:
* https://github.com/Wikia/config/pull/389
* https://github.com/Wikia/api-tests/pull/8