v.0.2.1: Bugfix: Duplicated releases

Fixed an issue where one release could appear several times.

v.0.2: Improvements for background task

Minor improvements, especially regarding background service that keeps releases up-to-date

v.0.1: First "official" version

• Checks for new album releases for all artists on phone using MusicBrainz
• Releases are displayed in two tabs: "Recently added" (within the last two weeks) and "All"
• Refreshs of the releases are performed daily
• When no internet connection available, refresh is postponed
• Availability of new releases are shown as notifications
• Available preferences: Time period (releases), download future releases, incremental/full update, use only wifi