Some browsers cannot handle very large DIVs so by default range DIVs
can be truncated outside the visible area. This change allows the use
of a new `limitSize` item option which disables this functionality,
allowing the creation of full-width DIVs.
I don’t see an existing test spec that covers RageItem.js so I’m
submitting without tests. However we’ve using Timeline in production on
a fairly large project with these changes in place for several months
and it works fine.