Depend on our cairo in GTK+ toolchain

Eventually we should try to just get this from XQuartz, but for now
let's depend on cairo for consistency.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/cairomm.rb

@@ -7,7 +7,7 @@ class Cairomm < Formula
 
   depends_on 'pkg-config' => :build
   depends_on 'libsigc++'
-  depends_on 'cairo' if MACOS_VERSION <= 10.6
+  depends_on 'cairo'
 
   def install
     system "./configure", "--disable-dependency-tracking",

Formula/gerbv.rb

@@ -7,7 +7,7 @@ class Gerbv < Formula
 
   depends_on 'pkg-config' => :build
   depends_on 'gtk+'
-  depends_on 'cairo' if MacOS.leopard?
+  depends_on 'cairo'
   depends_on :x11
 
   def install

Formula/gtk+.rb

@@ -14,6 +14,7 @@ class Gtkx < Formula
   depends_on 'pango'
   depends_on 'jasper' => :optional
   depends_on 'atk' => :optional
+  depends_on 'cairo'
   depends_on :x11
 
   fails_with :llvm do

Formula/pango.rb

@@ -10,16 +10,13 @@ class Pango < Formula
   depends_on 'glib'
   depends_on :x11
 
-  if MacOS.leopard?
+  depends_on 'fontconfig' if MacOS.leopard?
-    depends_on 'fontconfig' # Leopard's fontconfig is too old.
+
-    depends_on 'cairo' # Leopard doesn't come with Cairo.
+  # The Cairo library shipped with Lion contains a flaw that causes Graphviz
-  elsif MacOS.lion?
+  # to segfault. See the following ticket for information:
-    # The Cairo library shipped with Lion contains a flaw that causes Graphviz
+  #   https://trac.macports.org/ticket/30370
-    # to segfault. See the following ticket for information:
+  # We depend on our cairo on all platforms for consistency
-    #
+  depends_on 'cairo'
-    #   https://trac.macports.org/ticket/30370
-    depends_on 'cairo'
-  end
 
   fails_with :llvm do
     build 2326