Imported the unid() example.

Author: artob

doc/examples/unidgen.rb

@@ -0,0 +1,10 @@
+#!/usr/bin/env ruby
+require 'php'
+
+PHP.eval do
+  def unid
+    return md5(uniqid(mt_rand, true))
+  end
+
+  echo "#{unid}\n"
+end