ext/flac/: Remove backwards compatibility cruft for dealing with FLAC API changes in the 1.0.x series - we require 1....

Original commit message from CVS:
* ext/flac/Makefile.am:
* ext/flac/flac_compat.h:
* ext/flac/gstflac.c:
* ext/flac/gstflacdec.c: (gst_flac_dec_init):
* ext/flac/gstflacenc.c:
Remove backwards compatibility cruft for dealing with FLAC API
changes in the 1.0.x series - we require 1.1.1 or newer these days.