fmdiff: run make, update latest version, fix head

Run make in order to properly detect which version of XCode is
installed

Run make install instead of bin.install

Update to latest version which resolves the multiple symlink
layers issue.

Fixed head to use svn. Previous head didn't work (just downloaded
a single html file).

Closes Homebrew/homebrew#14143.

Signed-off-by: Misty De Meo <mistydemeo@gmail.com>

Formula/fmdiff.rb

@@ -2,12 +2,13 @@ require 'formula'
 
 class Fmdiff < Formula
   homepage 'http://www.defraine.net/~brunod/fmdiff/'
-  url 'http://www.defraine.net/~brunod/fmdiff/fmscripts-20120522.tar.gz'
-  sha1 'cdb98c68b617c8b42e714a906b7f3824c4c5afe9'
+  url 'http://bruno.defraine.net/fmdiff/fmscripts-20120813.tar.gz'
+  sha1 'a5342820893f61b29e1060527cc722ef51574911'
 
-  head 'http://soft.vub.ac.be/svn-gen/bdefrain/fmscripts/'
+  head 'http://soft.vub.ac.be/svn-gen/bdefrain/fmscripts/', :using => :svn
 
   def install
-    bin.install Dir["fm*"]
+  system "make"
+  system "make", "DESTDIR=#{bin}", "install"
   end
 end