Add http cookie passthrough to FFMPEG

cleanup after code review

add release

fix comments
videodb: add RemoveArtForItem()
jsonrpc: add possibility to remove artwork from video items
Merge pull request #3519 from Montellese/jsonrpc_art_removal

jsonrpc: add possibility to remove artwork from video items
videodb: add GetSeasonInfo()
videodb: add SetDetailsForSeason()
jsonrpc: return "seasonid" in VideoLibrary.GetSeasons
jsonrpc: add VideoLibrary.GetSeasonDetails
jsonrpc: add VideoLibrary.SetSeasonDetails
Merge pull request #3480 from micahg/master

Add http cookie passthrough to FFMPEG
Merge pull request #3520 from Montellese/jsonrpc_season

jsonrpc: improve season support
fix build after 9dda8b3bb09543455da27899a6f9df0b6cb086d8
jsonrpc: add support for multiple items to Playlist.Add/Insert
Merge pull request #3413 from Montellese/jsonrpc_playlist_additems

jsonrpc: add support for multiple items to Playlist.Add/Insert