Release 3.1.0rc1 is a release candidate aimed primarily at ironing out bugs
in HTML Purifier's shiny new __autoload system.  There are lots of new features,
however; some notable ones include support for the !important CSS modifier,
display and visibility CSS properties with %CSS.AllowTricky, marquee
with %HTML.Proprietary (had you scared for a moment, hmm?), a kses() wrapper,
%CSS.AllowedProperties, %HTML.ForbiddenAttributes and %HTML.ForbiddenElements
and a totally revamped ConfigDoc system. And of course, the usual slew of
bugfixes.