[dcc2] MultiFile Transfer Headers

[codemastr]

> IRC already uses seconds since epoch in many places, so any IRC client
> will already have parsers and formatters for this.  Plus, I think that a
> 64-bit signed integer is easier to parse than ISO 8601.
I like using epoch time. It's probably the easiest to implement. On *nix,
you simply plop it right in, since the system uses epoch time, and on
Windows, you just have to convert it to MS's insane nanosecond format. ISO
8601 is a bad idea in my mind, it complicates things. Now you have to parse
the text and convert it to an integer. Same with RFC822. Those things were
designed for _human readable_ date/times. They are designed to be the
easiest for people. A DCC2 message, however, is designed to be read by a
machine. Would it not then make sense to format the time in such a way that
is easy for a machine to understand? Though personally, I'm still against
timestamps altogether. People are saying it's useful, I've yet to see anyone
say how it is useful. The only thing I can think of is some kind of
"caching" system in which you do not download the file if it is older than
the one you already have. However, since we're already sending an SHA1,
checking the SHA1 would be a *much* more accurate way of determining if the
file changed. Checking the SHA1, and the filesize would provide almost no
chance that you have a false positive. But, I personally don't think DCC
should support caching anyway. Other than that, I can't see any use for it.

-- codemastr