contrib: add missing fluidsynth libs for static linking

Putting these in pkg-config is a bit of ugly, but it makes sense since
we only build a static library. As a reference, upstream libav does the
exact same thing already.

contrib/src/fluid/fluid-pkg-static.patch

+diff -ru fluidsynth.orig/fluidsynth.pc.in fluidsynth/fluidsynth.pc.in
+--- fluidsynth.orig/fluidsynth.pc.in	2011-08-03 10:45:08.000000000 +0300
++++ fluidsynth/fluidsynth.pc.in	2011-08-03 10:45:51.000000000 +0300
+@@ -6,5 +6,5 @@
+ Name: FluidSynth
+ Description: Software SoundFont synth
+ Version: @VERSION@
+-Libs: -L${libdir} -lfluidsynth
++Libs: -L${libdir} -lfluidsynth -lgthread-2.0 -lglib-2.0 -lm
+ Cflags: -I${includedir}

contrib/src/fluid/rules.mak

@@ -21,6 +21,7 @@ ifeq ($(call need_pkg,"glib-2.0"),)
 FLUID_TARBALL := fluidsynth-$(FLUID_VERSION).tar.bz2
 else
 FLUID_TARBALL := fluidsynth-1.0.9.tar.gz
+FLUID_VERSION := 1.0.9
 endif
 
 fluidsynth: $(FLUID_TARBALL) .sum-fluid
@@ -28,6 +29,9 @@ fluidsynth: $(FLUID_TARBALL) .sum-fluid
 	$(APPLY) $(SRC)/fluid/fluid-no-bin.patch
 ifdef HAVE_WIN32
 	$(APPLY) $(SRC)/fluid/fluid-static-win32.patch
+endif
+ifneq ($(FLUID_VERSION),1.0.9)
+	$(APPLY) $(SRC)/fluid/fluid-pkg-static.patch
 endif
 	$(MOVE)