Added tests for "ignored" comments.
Added tests for "ignored" comments.

AshKyd/html-minifier,AshKyd/html-minifier,kangax/html-minifier,bryanerayner/html-minifier,kangax/html-minifier,bryanerayner/html-minifier,kangax/html-lint,jonnochoo/html-minifier,HossainKhademian/HtmlMinifier,DChristiany/html-minifier,kangax/html-lint,GerHobbelt/html-minifier,psychoss/html-minifier,psychoss/html-minifier,jonnochoo/html-minifier,MacManus/html-minifier,GerHobbelt/html-minifier,DChristiany/html-minifier,MacManus/html-minifier