Changed not to escape quotes while interpolating CDATA section. #11

Escaping quotes in plain text node is not necessary.
PHP 5.4 compatibility: Short tag <?= is always enabled.
Reverted choosing escape option for quotes in CDATA section. #11
Added HTML5 boolean attributes. #8 #10
Added HTML5 empty tags. #10
Remove an older duplicate test.
Merge pull request #12 from pornel/html5tags

Empty tags and empty attributes definition for HTML5