Merge branch 'html5-tag-parsing'
Deprecated preg_replace() /e modifier in PHP5.5+

Replacing instances of preg_replace() that use the /e modifier to
preg_replace_callback() in order to future-proof Cindy.
Merge pull request #3 from karlding/deprecated-php-features

Merged fix for deprecated PREG_REPLACE_EVAL modifier into master branch.