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…

- two options request/ack_message_receipts
- two new theme parameters : CHAR_ACK_RECEIVED and COLOR_CHAR_ACK
- if a message has a receipt, the character is displayed between the
  timestamp and the nick, using the color

- destroy the current room if no parameter
- destroy the room given as a parameter if any
- no reason or alt room because it would be ambiguous in a command
  (implementation ideas welcome)

(SIGTERM, SIGHUP, and SIGPIPE for now)

- also fix some erroneous comment(s)
- remove self.background which wasn’t set to something other than false
- fix the chatroom address (and the doc) in the first help message

wrap some curses calls with try/except block

- add a show_composing_tabs option, default value: "direct"
- todo: find a nice different color for this

- fallback to mediated invitations if only the bare jid is given to the
  command or if the jid does not advertise support

TODO: provide a way to send passwords

It was actually doing that for old python version but not recent onces

fixes whitespace issues, some builtin overrides, and some enormous lines

might make poezio run nanoseconds faster!

as it is unused code anyway.

Although the logic stays the same, and everything is put back together
in a single class.