move stream (i.e. not torrent) handeling code to a more generic place

Signed-off-by: Niv Sardi <xaiki@evilgiggle.com>
factorize calcHealth to it's own function

Signed-off-by: Niv Sardi <xaiki@evilgiggle.com>
support for '480p' quality,

really all this code should be reactive to the keys in torrents more than anything

Signed-off-by: Niv Sardi <xaiki@evilgiggle.com>