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

that was ugly

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

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

might make poezio run nanoseconds faster!

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delayed execution is cleaner and less error-prone

fixes some bugs when closing tabs that disable it

- avoid doing stringprep on every item, avoid at least one full copy
- add the number of items to the infowin

as it is unused code anyway.

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

- /bookmark{_local,} * now keeps the order of the tabs, and puts the
  currently non-opened tabs at the end of the list.
- also fix a bug in remote bookmark saving

(thanks eijebong)

TODO: check if this method of setting activity isn’t a bit heavy.

remove xhtml prior to performing stuff

Now everything in the logs is in UTC time, and is converted when read

(also, actually return the logs after loading them instead of not doing
anything)

only happens with buggy servers (hello ejabberd)