Fixes in entity and HTML block parsing

- HTML blocks would sometimes run together due to insufficient
  whitespace between them. Fixed.
- HTML entities would cause XMLS to flip its lid. They are now escaped
  pre-HTML-parse and unescaped post-HTML-parse.
- XMLS was counting things as entities that were clearly not entities.
  Fixed with the above mentioned entity fixes.

Not including tests with this commit because it's hard to get XMLS to
ignore HTML entities (ie, non-numbered entities) and I'd rather just get
the fix out.