seek from lowest level (true/false)
add a new customization parameter to tweak the adaptive switching logic when seeking to a new position
if set to true, HLSProvider will switch to lowest level when seeking
if set to false (default value), HLSProvider will keep using same level
customizable in jwplayer/flowplayer/chromeless Player
related to https://github.com/mangui/HLSprovider/issues/128