Use a placeholder object that can run it afterwards, so that we don’t
have side effects inside those functions.

And wipe the YesNoInput from the codebase

fixes the circular import issue

All this crap is very brittle due to circular deps and python handling
them badly. This appears to be fixing some stuff, at the very least.

This is sed, so cleanup of imports (which can now be grouped together)
is not done yet.

(the line above was never used and could contain garbage from elsewhere)
TODO: fix the way we arrange information inside it to fit more stuff

(for easier API access)

fix #3076

- slightly lower the CPU usage (callback instead of active waiting w/ sleep)
- make the terminal beep so the user knows something happened
- prevent the user “escaping” the prompt by pressing /, s, or S

- Add two new options, keyfile and certfile, which must be both set for
  the auth to work.
- if both are set, then poezio doesn’t force-prompt a password if there
  is none specified
- add /cert_add, /cert_fetch, /cert_disable, /cert_revoke and /certs
  commands.
- add a page of documentation on the process

Avoid surprises with some commands accepting quoted arguments and some other
not.

fix #2555

The /reconnect command should now properly work everytime.

This reverts commit b46f0f5e.

Conflicts:
	src/tabs/muclisttab.py

Doing this made the unresized elements refresh in the old subwins,
causing glitches and weirdness. And anyway, the only problematic
element is the TextWin (rebuilding all the lines of a buffer is
expensive), but it already checks if the width changed.

(keep a get_name() fallback just in case for now)

some stuff is now hidden wen the window size gets too small (might need
some adjustments). The info buffer in the roster tab, the userlist in
mucs, the vertical tab list, the info buffer everywhere, etc…

config.get('option', 'value').lower() == 'value' is just ugly and
stupid, especially for bool.

One if in basetabs:556 was also missing a comparison, leading to True
whenever the option was set.

- No idea why subclasses of ConversationTab were working before
    (info_header was overriden with None in __init__)
- Or why the date parsing worked (“Exeception”)
- Some more reformatting with pylint indications
- Document each module in the tabs module

- todo: write a common import file to avoid duplicating the imports