mpd: fix a number of build issues

- When yajl is installed, the build system manages to find it even
   under superenv, so explicitly disable this option unless requested
 - Future-proof finding faad2 in non-/usr/local installs
 - Fix libshout deps

Formula/libshout.rb

@@ -8,13 +8,11 @@ class Libshout < Formula
   depends_on 'pkg-config' => :build
   depends_on 'libogg'
   depends_on 'libvorbis'
-
-  depends_on 'theora' => :optional
-  depends_on 'speex'  => :optional
+  depends_on 'theora'
+  depends_on 'speex'
 
   def install
-    system "./configure", "--disable-debug", "--disable-dependency-tracking",
-                          "--prefix=#{prefix}"
+    system "./configure", "--disable-dependency-tracking", "--prefix=#{prefix}"
     system "make install"
   end
 end

Formula/mpd.rb

@@ -8,7 +8,8 @@ class Mpd < Formula
   head "git://git.musicpd.org/master/mpd.git"
 
   option "lastfm", "Compile with experimental support for Last.fm radio"
-  option 'libwrap', 'Enable support of TCP Wrappers (buggy on 10.7)'
+  option "libwrap", "Enable support of TCP Wrappers (buggy on 10.7)"
+  option "enable-soundcloud", "Enable support for soundcloud.com"
 
   depends_on 'pkg-config' => :build
   depends_on 'glib'
@@ -18,29 +19,33 @@ class Mpd < Formula
   depends_on 'libshout'
   depends_on 'mad'
   depends_on 'lame'
-  depends_on 'faad2' => :optional
   depends_on 'fluid-synth'
+  depends_on 'libshout'
+  depends_on 'faad2'
   depends_on 'libmms' => :optional
   depends_on 'libzzip' => :optional
+  depends_on 'yajl' if build.include? 'enable-soundcloud'
 
   def install
     system "./autogen.sh" if build.head?
 
-    # make faad.h findable (when brew is used elsewhere than /usr/local/)
-    ENV.append 'CFLAGS', "-I#{HOMEBREW_PREFIX}/include"
+    args = %W[
+      --disable-debug
+      --disable-dependency-tracking
+      --prefix=#{prefix}
+      --enable-bzip2
+      --enable-ffmpeg
+      --enable-flac
+      --enable-shout
+      --enable-fluidsynth
+      --enable-lame-encoder
+      --with-faad=#{Formula.factory("faad2").opt_prefix}
+    ]
 
-    args = ["--disable-debug", "--disable-dependency-tracking",
-            "--prefix=#{prefix}",
-            "--enable-bzip2",
-            "--enable-ffmpeg",
-            "--enable-flac",
-            "--enable-shout",
-            "--enable-fluidsynth",
-            "--enable-lame-encoder"]
-
-    args << "--enable-zzip" if build.with? "libzzip"
     args << "--disable-curl" if MacOS.version == :leopard
-    args << "--enable-lastfm" if build.include?("lastfm")
+    args << "--disable-soundcloud" unless build.include? "enable-soundcloud"
+    args << "--enable-zzip" if build.with? "libzzip"
+    args << "--enable-lastfm" if build.include? "lastfm"
     args << "--disable-libwrap" unless build.include? 'libwrap'
 
     system "./configure", *args