Don't crash with missing optional args to css

On Mon, Oct 06, 2014 at 10:29:58 -0700, Dylan Simon wrote:
> Basically a rewrite in haskell with some custom database stuff for
> bookmarks: https://github.com/dylex/huzblem I suspect I'm more the
> exception than the rule. I know at least one other person who was
> using the stock daemon at some point, and I bet most people use it as
> is out of the box.

Heh. I had a project *long* ago called huzbl on my machine I was poking
around with. I think at least getting the list of features provided in
various EM implementations would be good.

For example, I really want to write up RequestPolicy and
HTTPS-Everywhere plugins for uzbl, but Python3 performance is
less-than-stellar, so something else would be nice to work with, but I'd
like to take a survey first (unfortunately, Haskell's runtime is
probably "too heavy" for many who are uzbl's target audience; hell,
someone mentioned to me that they'd like to make an EM in shell).