Feature: Add the possibility to pipe the config to he command

[BananaAcid]

I need to call the command with single accounts, so providing all params for it to the command would be helpful.

To not make it too complicated (by adding all possible options as params like imapsync does), it would probably be quicker to add some functionality to be able to pipe the config to the command.

(I have no idea of python. I googled, that Python ConfigParser can read from buf. Which can be filled by with the piped content, I guess)

Feature usage like: (scroll to the end)

$ echo $'[imapbox]\nlocal_folder=/var/imapbox\ndays=6\nwkhtmltopdf=/opt/bin/wkhtmltopdf\n\n[account1]\nhost=mail.autistici.org\nusername=username@domain\npassword=secret\nssl=True' | python3 imapbox.py

[polo2ro]

I would be favorable to DSN description of an account, something like imap://[email protected]:[email protected]:993/INBOX?ssl=true symfony does such thing for smtp: https://symfony.com/doc/current/mailer.html

[BananaAcid]

I do have a version ready to support DSNs (as param as well as in the config block combining with the available options) without breaking anything, and will create a pull request