Added formula for autotrace utility

Autotrace is a small utility for tracing bitmap files to vector graphics. The tool has been updated years ago, but still works and compiles nicely.
As default it is compiled with ImageMagick (as the default configure script would do). To disable it set "--without-imagemagick"

Signed-off-by: David Höppner <0xffea@gmail.com>

Formula/autotrace.rb

@@ -0,0 +1,32 @@
+require 'formula'
+
+def without_imagemagick?
+  ARGV.include? '--without-imagemagick'
+end
+
+class Autotrace <Formula
+  url 'http://downloads.sourceforge.net/project/autotrace/AutoTrace/0.31.1/autotrace-0.31.1.tar.gz'
+  homepage 'http://autotrace.sourceforge.net'
+  md5 '54eabbb38d2076ded6d271e1ee4d0783'
+
+  depends_on 'libpng'
+  depends_on 'imagemagick' unless without_imagemagick?
+
+  def options
+    [
+      ['--without-imagemagick', 'Compile without ImageMagick (non-bloaty)']
+    ]
+  end
+
+  def install
+    args = [  "--disable-debug",
+              "--disable-dependency-tracking",
+              "--prefix=#{prefix}",
+              "--mandir=#{man}" ]
+
+    args <<  "--without-magick" if without_imagemagick?
+
+    system "./configure", *args
+    system "make install"
+  end
+end