* Use absolute paths to load gobject, pango and cairo.
* Add xcb-cursor support (also with absolute path)
* Avoid tainting child processes environment:
Save PATH and PYTHONPATH in wrapper, and restore them in python code.
* Alter restart process, using $0 saved in wrapper, which allow user
to restart qtile after system rebuild to upgrade it.
The most complex problems were from dealing with switches reverted in
the meantime (gcc5, gmp6, ncurses6).
It's likely that darwin is (still) broken nontrivially.
This seems to have been confusing people, using both xlibs and xorg, etc.
- Avoided renaming local (and different) xlibs binding in gcc*.
- Fixed cases where both xorg and xlibs were used.
Hopefully everything still works as before.
