Fix for error in parsing particular incorrect singletons.
Fix for error in parsing particular incorrect singletons.

When the HTML parser attempts to parse tags that should be
singletons but are not, AND they have content, an exception
occurs:

  1> mochiweb_html:parse("<html><input><input>x</input></input></html>").
  ** exception error: no case clause matching
        	            {[],[{<<"input">>,[],[<<"x">>]},{<<"input">>,[],[]}]}
       in function  mochiweb_html:destack/2
       in call from mochiweb_html:tree/2
       in call from mochiweb_html:parse_tokens/1

This patch provides a fix.

ubf/mochiweb,mdg/mochiweb,GOFactory/mochiweb,rabbitmq/mochiweb,tsingpan/mochiweb,RJ/mochiweb-websockets,danogwok/mochiweb,jasonjli/mochiweb,kuenishi/mochiweb,danogwok/mochiweb,vinoski/mochiweb,robertkowalski/mochiweb,vinoski/mochiweb,riak-synrc/mochiweb,heroku/mochiweb,tsingpan/mochiweb,jasonjli/mochiweb,GOFactory/mochiweb,rabbitmq/mochiweb,rcouch/couchdb-mochiweb,robertkowalski/mochiweb,ubf/mochiweb