Contribs: Fix FLAC.pc for Windows

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

contrib/src/flac/libFLAC-pc-win32.patch

+--- flac/src/libFLAC/flac.pc.in	2013-01-04 00:05:04.000000000 +0100
++++ flac.new/src/libFLAC/flac.pc.in	2013-03-19 00:54:54.000000000 +0100
+@@ -6,6 +6,6 @@
+ Name: FLAC
+ Description: Free Lossless Audio Codec Library
+ Version: @VERSION@
+-Libs: -L${libdir} -lFLAC -logg -lm
++Libs: -L${libdir} -lFLAC -logg -lm -lws2_32
+ Cflags: -I${includedir}/FLAC
+ Requires.private: ogg

contrib/src/flac/rules.mak

@@ -17,6 +17,9 @@ flac: flac-$(FLAC_VERSION).tar.gz .sum-flac
 	$(UNPACK)
 	$(APPLY) $(SRC)/flac/flac-win32.patch
 	$(APPLY) $(SRC)/flac/libFLAC-pc.patch
+ifdef HAVE_WIN32
+	$(APPLY) $(SRC)/flac/libFLAC-pc-win32.patch
+endif
 ifdef HAVE_MACOSX
 	cd $(UNPACK_DIR) && sed -e 's,-dynamiclib,-dynamiclib -arch $(ARCH),' -i.orig configure
 endif