Implement currentPlaylistService, queueService, and playlistService

Add jsdoc comments in providersService

Implement playlistService

qupdate queueService

Remove stray space from index.html

Add currentPlaylistService

Added utility functions to queueService

update playlistService
Update jsDoc notation and fix bug in eventService
Merge pull request #336 from alexmckenley/queuePlaylist

Implement currentPlaylistService, queueService, and playlistService