Now there is a new synchronous method Player.isBrowserSupported. This
will detect basic support and return a boolean. The support() method
has been renamed to probeSupport() and should only be used for
diagnostics.
Also added a plugin system to Player support testing. Now a plugin
(e.g. offline) can add extra info to the output of probeSupport().
Closes#388Closes#389
Change-Id: I313a41d9f123871272f1395aeb99c980df1f4bae