Adventist Hymnal Complete

Oct 16, 2019

- We rewrote the implementation of the audio player in the background
- Implemented the automatic play of the next and previous hymn directly on the media player
- Added the progress time of the hymns being play
- Bug fixes in the random and sequential playing of hymns
- We implemented redundancy between 3 servers for audio downloads
- Fixes for audio play in the background for android 8+
- We simplified the Easy mode on the only text hymnal.