[fix] The `isSelfClosing` method detection was based on a regexp, but in HTML5 self closing slashes are optional
[fix] The `isSelfClosing` method detection was based on a regexp, but in HTML5 self closing slashes are optional

This caused the code to add to much openers which in it's result caused that large chumbs of code to be removed
as matchmode was never set back to false as the check required openers to be less or equal to 0.

abravalheri/plates,flatiron/plates,abravalheri/plates