gtkmm3 3.4.2

Closes Homebrew/homebrew#15238.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Formula/gtkmm3.rb

@@ -0,0 +1,21 @@
+require 'formula'
+
+class Gtkmm3 < Formula
+  homepage 'http://www.gtkmm.org/'
+  url 'http://ftp.gnome.org/pub/GNOME/sources/gtkmm/3.4/gtkmm-3.4.2.tar.xz'
+  sha256 '760c01bca693d26558eb5eae0cf6c743a6bb453258a633f78de506e3c98262b4'
+
+  depends_on 'xz' => :build
+  depends_on 'pkg-config' => :build
+  depends_on 'glibmm'
+  depends_on 'gtk+3'
+  depends_on 'libsigc++'
+  depends_on 'pangomm'
+  depends_on 'atkmm'
+  depends_on :x11
+
+  def install
+    system "./configure", "--disable-dependency-tracking", "--prefix=#{prefix}"
+    system "make install"
+  end
+end