* amended transcript popup, expandable, enabled auto scroll
* on topbar of EpisodeInfo, added item to fetch transcript (only applicable for external media)
* in MediaPlayer
	* when error on playing external media, toast about playing again or reset clients connection
	* when playing curMedia after stream url expire time, ensure to refetch stream url
* transcript meta data of external source media are cleared on expire in PlayerDetailed and EpisodeInfo
