some progress on reading mail

I am delighted to report that Data (the Ark) is now able to read email from both imap and pop3 servers, posting them to $cd (current day) in the calendar.

Works great, but for two issues:

1. Too many headers are created! For now I plan to suppress the display of selected headers. Later this should be configurable.
2. Crash and burn on multi-part mime email. I need to create separate LSecs for each part.

I don't think this is going to take too long. But then we need a way to view attachments. :-(