Sending email is not our core business. The option can be easily 
replaced with a pre or post hook script. And its implementation 
requires complicated low-level fiddling with exception handlers and 
temporary files, see redirectOutput In ApplyPatches and withStdoutTemp 
which is implemented in darcs.Util.Compat.

I think this is sensible. I had a quick look on darcs.net and I
don't think we're using --reply there, instead there's a posthook.

We should also drop the --cc and --sendmail-command from apply
at the same time.

However, darcs send also sends email and is useful, at least for
us as long as we have the current patch tracker. How much of the 
nasty code is specific to apply?

See patch1742 for details of what will be removed. Sending email via 
darcs send is not affected.