Merge pull request #7 from blakink/master

Allow custom user_agent
Mass rewrite
Cleaning up
Updated readme, travis file
Fixed ruby version in travis config
Readme and travis
Fix exception while writing utf8 to cache
Align directory structure of specs with lib.
Handle different cases of release's format attribute.
Merge pull request #9 from Applicat/parse_multiple_cd_format_correctly

Consider different cases of release's format attribute.
Stability improvements, new release
Failsafe proxy fix
Implements MusicBrainz::ReleaseGroup.search and .find_by_artist_and_title
Adds release fields asin, barcode and quality.
Merge pull request #13 from Applicat/add_asin_attribute_to_release2

Adds release fields asin, barcode and quality.
Merge pull request #12 from Applicat/release_group_search2

Implementation of release group search
Calculate last day of month correctly. refs #14
Fixes typo.
Adds type field to release model.
Adds type field to release model.