Add a method to perform get_range typefinding that also uses the
uri/location extension as an extra hint. It will first try to call the
typefind functions of the factories that handle the given extension. The result
is that in the common case, we only call one typefind function, which speeds up
the typefinding a lot.
Original commit message from CVS:
Added typefind helper.
Small preroll fix in the base sink.
Disable typefind code in basesrc.
Crude port of typefindelement.
Fakesrc cleanups.