Contribs: update FLAC to 1.3.0pre2

contrib/src/flac/SHA512SUMS

-39b216239341fbfe210c3a2fc0d0531ecae26c425365c4b6d4fc1081e44e6dc7a9aba8d4c79cc8025386d0a7bb0d25c413c9b64cf7da9ab04ca34a56d2699787  flac-1.2.1.tar.gz
+cc4ec1d5f89a5b674cd66d4fcbd1f34c5ee141cbe4e6978e9d5d55701be95442038d39daba2b8ca31914e9a8d54071f19d1b8c0e08af77a559e94d60d8074f5c  flac-1.3.0pre2.tar.xz

contrib/src/flac/libFLAC-pc.patch

---- flac/src/libFLAC/flac.pc.in	2007-02-07 02:07:32.000000000 +0100
-+++ flac.new/src/libFLAC/flac.pc.in	2011-06-10 17:53:44.337825845 +0200
+--- flac-1.3.0pre2/src/libFLAC/flac.pc.in.orig	2013-03-10 13:19:01.140663514 +0100
++++ flac-1.3.0pre2/src/libFLAC/flac.pc.in	2013-03-10 13:20:46.398688639 +0100
 @@ -6,5 +6,6 @@
  Name: FLAC
  Description: Free Lossless Audio Codec Library
  Version: @VERSION@
 -Libs: -L${libdir} -lFLAC -lm
 +Libs: -L${libdir} -lFLAC -logg -lm
- Cflags: -I${includedir}/FLAC
+ Cflags: -I${includedir}
 +Requires.private: ogg

contrib/src/flac/rules.mak

 # FLAC
 
-FLAC_VERSION := 1.2.1
-FLAC_URL := $(SF)/flac/flac-src/flac-$(FLAC_VERSION)-src/flac-$(FLAC_VERSION).tar.gz
+FLAC_VERSION := 1.3.0pre2
+FLAC_URL := http://downloads.xiph.org/releases/flac/beta/flac-$(FLAC_VERSION).tar.xz
 
 PKGS += flac
 ifeq ($(call need_pkg,"flac"),)
 PKGS_FOUND += flac
 endif
 
-$(TARBALLS)/flac-$(FLAC_VERSION).tar.gz:
+$(TARBALLS)/flac-$(FLAC_VERSION).tar.xz:
 	$(call download,$(FLAC_URL))
 
-.sum-flac: flac-$(FLAC_VERSION).tar.gz
+.sum-flac: flac-$(FLAC_VERSION).tar.xz
 
-flac: flac-$(FLAC_VERSION).tar.gz .sum-flac
+flac: flac-$(FLAC_VERSION).tar.xz .sum-flac
 	$(UNPACK)
-	$(APPLY) $(SRC)/flac/flac-win32.patch
 	$(APPLY) $(SRC)/flac/libFLAC-pc.patch
 ifdef HAVE_DARWIN_OS
 	cd $(UNPACK_DIR) && sed -e 's,-dynamiclib,-dynamiclib -arch $(ARCH),' -i.orig configure