A user may want to be able to see what mimetype they are viewing, so
that they can determine what program it may be opened in or for some
other reason.
The config option is under the [viewer] section and is called
'always-show-mime'. It defaults to false to preserve the current
behaviour.
Adds an archive command that moves the current message into the folder
specified in the account config entry.
Supports three layouts at this point:
- flat: puts all messages next to each other
- year: creates a folder per year
- month: same as above, plus folders per month
This also adds a "-p" argument to "cp" and "mv" that works like
"--parents" on mkdir(1). We use this to auto-create the directories
for the archive layout.