updated activesupport for rails 4
require_relative for ruby 1.9.2+
bump version 2.1.0 and docs for rails 4
Merge branch 'rails4' of https://github.com/kcorbitt/openlibrary into kcorbitt-rails4

* 'rails4' of https://github.com/kcorbitt/openlibrary:
  bump version 2.1.0 and docs for rails 4
  require_relative for ruby 1.9.2+
  updated activesupport for rails 4

Conflicts:
	README.rdoc
	lib/openlibrary/version.rb