Add feature detection for MediaSource support in reference player

Created by: wilaw

v0.0.7 of the reference build fails silently if loaded in a browser that does not support MSE. Player should perform a feature check when loaded and verify that MSE APIs are available. If available, load player UI and instantiate all page elements. If not available, display a clear UI message about which browser APIs are necessary for the correct operation of the player and some type of helpful suggestion as to where to obtain (or update) such a browser.

Use feature detection to make this decision, versus inference through browser version checking. Create check code in a separate reusable class that may one day be used as a basis for MS feature categorization i.e if (when :) )there is browser fragmentation, be able to branch player code based on deterministic feature support.