More packages ported

[Igor Khavkine <i_khavki@alcor.concordia.ca>]

Hi, I've just looked at a couple more packages to build on Hurd.
They are

libgc5 - patch taken from Chris Lingard <chris@highludworth.freeserve.co.uk>
w3m 
smail

All build and work properly (tested). I've submitted the appropriate
patches as bugs to Debian maintainers. Jeff, once the patches
are applied, you can add them to the autobuilder.

BTW, I remember there was a lot of fuss about exim working or not
working. I tested  smail and it seems to work, could be a
substitute in the mean time.

Igor