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

fix #2555

Make the "default" parameter optional and thus move it to the end of
the command with the other optional parameters.

And change all the calls.

and not the global info buffer

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)

(also, fix a traceback-typo)

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…

- fix the /version completion with spaces
- fix the /unignore completion with spaces

also remove some hardcoded stuff

(it now uses the theme)

thanks gio

also clean up some newlines mess

- now it should work properly
- add a COLOR_LOG_MSG theming option, used both for local and remote
  history

(thanks eijebong)

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