Add native HLS support for Safari on OSX

- Remove improper HLS mimeTypes for HLS video: 'application/mpegurl' and added proper one for HLS audio: 'application/x-mpegurl'
- Fix comparison of declared mimeType in item config and that from iLove model array to be case insensitive, cause mimeTypes are case insensitive (RFC2045)
- x- prefix is now left if it's declared cause it's an important part of mimeType E.g. Safari on OSX returns 'maybe' for canUseType('application/x-mpegurl') but empty string for canUseType('application/mpegurl')