Ruby compatibility issues

- regexp engines are different from 1.8 to 1.9, fixed the literal shorthand regexp accordingly
  - changed the shorthand regexp text from a match to a string scan
  - test_helper now loads rubygems unless RUBY_VERSION is > 1.9

test/test_helper.rb

@@ -2,6 +2,7 @@
 extras_path = File.join File.dirname(__FILE__), 'extra'
 $LOAD_PATH.unshift(extras_path) unless $LOAD_PATH.include? extras_path
 
+require 'rubygems' unless RUBY_VERSION =~ /^(?:1.9.*)$/
 require 'test/unit'
 require 'test/unit/assertions'
 require 'caller'