Restore video tag attributes on tech change

New attempt to fix this issue #1367 related to the webkit-playsinline attribute missing.
getTagSettings is a static method (as much as javascript permit it), accessing an attribute of the instance on this method seams strange to me, even if the reality is that we only use this method on the constructor. I don't think it's wrong but to make it right this imply more work, rename the method, remove the arguments, do you have a convention for "private" methods ?