[dev] Simple session support for surf

The attached patch sucks too much for mainline, but some may find it
useful. I do.

The concept is a simple session system inspired by the one found in
Firefox, where you can easily suspend surf and later continue from where
you left off (across system boots). It also means you can easily
continue when (not if) surf crashes. Because the system is so simple,
only the visited URL is stored, not the deeper context (like history).
This may be worth fixing, and would not be excessively hard.

The patch depends on the following rc shell script, which does the
actual session handling.

-- 
\  Troels
/\ Henriksen