List of things to do.

* pgp_old is completely unimplemented

* -u doesn't check for multiple signing keys specified

* error codes need to be more rigorous to enable reasonable scripting

* keyserver support should be a little more informative when you enter
a protocol it doesn't support.  Also, I need to port all of the
connections error messages from the Windoze version; right now, if
(i.e.) you enter a nonexistant hostname, you don't get a warning
message.

* url.c needs to be rewritten to handle dynamic allocation for URL
parsing instead of using static buffers

* The PAGER directive in config.txt doesn't work.

* Verbosity levels aren't particularly implemented

