Created documentation for Intl extension
merged branch naitsirch/master (PR #87)

This PR was squashed before being merged into the master branch (closes #87).

Discussion
----------

Created documentation for Intl extension

Created documentation for Intl extension. It would be nice if this could be integrated. Otherwise it's hard to find the `localizeddate` filter and the needed arguments.

Thanks for this extension ;-)

Commits
-------

138403a Created documentation for Intl extension
modernized the way unit tests are handled
fixed tests for PHP 5.4