We get a significant speed improvement of >10% by rearranging filter
operators to bring to the front the operators likely to reduce the size
working list.
The problem was that the scrollable required that the mouse be over the
story river itself in order to scroll it with the wheel. If we fallback
to scrolling the story by scrolling the browser body then we are able
to scroll even if the mouse is over the sidebar.
Fixes#82.
The old behaviour was to parse the content of a widget or html element
in block mode if the opening tag was followed by a line break. The new
behaviour requires two line breaks.
This makes it possible to include linebreaks more liberally within
wikitext, although care must still be taken to only use double line
breaks when the block mode behaviour is desired.
The code change here is very simple, just a single line change in
html.js. Most of the other changes are to convert various single line
breaks into double line breaks.
