Closes #641

Closes #643

Closes #642

All supported browsers have this method.

test="<a href=# onclick=\"alert(); return false;\">test</a>";

Previous (incorrect) behavior was:
test="<a href=# onclick=\"alert();
   return false;
\">test</a>"

Issue #627

Move to a slight variation of the old code again, since the new one
had some serious problems.

Spaces at the end of the line cause different wrapping in that
engine.

Implicit conversion to bool was used where ==null was intended.

Closes #624

Issue #616

Issue #606

Closes #616

Issue #606

Things like browser search could set its scrollTop to something >0, in which
case our whole scrolling would get stuck in a broken state. This makes sure to
reset it back to zero when that happens.

- Changed to read the tagName from state.htmlState instead of state.htmlState.context on '>'.  xml.js has expanded its awareness of void html tags and is popping its context when it doesn't expect a close tag.
- Added an option defining a list of void tags.