Added installation formula for SSSS (Shamir's Secret Sharing Scheme)

- Updated per requests in the issue comments by adamv
- Updated to pass compiler flag -DNOMLOCK avoiding OS X warning on run.

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

* add CFLAGS so gmp.h is picked up in non /usr/local

Formula/ssss.rb

@@ -0,0 +1,27 @@
+require 'formula'
+
+class Ssss <Formula
+  url 'http://point-at-infinity.org/ssss/ssss-0.5.tar.gz'
+  homepage 'http://point-at-infinity.org/ssss/'
+  md5 '24227252aa195a146d09de1df10357a1'
+
+  depends_on 'gmp'
+  depends_on 'xmltoman'
+
+  def install
+
+    inreplace 'Makefile' do |contents|
+      # Compile with -DNOMLOCK to avoid warning on every run on OS X.
+      contents.gsub! /\-W/, '-W -DNOMLOCK $(CFLAGS) $(LDFLAGS)'
+      contents.change_make_var! "CC", ENV.cc
+    end
+
+    ENV.append 'CFLAGS', "-I#{HOMEBREW_PREFIX}/include"
+    system "make"
+    prefix.install %w{ HISTORY LICENSE THANKS }
+    man1.install %w{ ssss.1 }
+    bin.install %w{ ssss-combine ssss-split }
+  end
+
+end
+