Add core_ext string with random method
Add test gems into bundler.

Use datamapper adapter and sqlite3 for testing purpose.
Support for R18n

Add locales.
Add Setting.default_locale to config file.
Add r18n-core gem.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	Gemfile
	lib/rubycas-server-core/core_ext.rb
	rubycas-server-core.gemspec
	spec/rubycas-server-core/core_ext_spec.rb
	spec/rubycas_server_core_spec.rb