reorganize code

move all code to / and have only a main package. don't bother making up packages, we never gonna use them anywhere else.

lots of things

list: print emails while reading them

don't read all emails and print them, but read all filenames and parse/print emails as we go.

make account a *Mailbox; small fixes to code and readme

use int64 instead of string for msg id - nmh is about numbered files; improve mh.Append

simplify some code; use Message instead of *Message, this struct is small

throw away interfaces; mailbox will be a nmh mailbox client only

implement edit case in main; other small fixes

grep msg body

rename 'pick' to 'grep'

improved pick: now its possible to specify 1..n header keys for searching

mail is moved to sent folder after sending

fix attach

add MIME-Version to mime header

write \n instead of \r\n in email header, seems that the rfc is not followed by anyone

sent first mail with mailbox!

fix package declarations of mh package

simplify save and parts cmd by replacing channels with string slices

rewrote sequences so i can use it for mime parts

lots of small improvements