[devtools] fix a couple issues with xvfb-run xvfb-run didn't quite clean up correctly after itself, because: - dash doesn't run EXIT traps on signals - if we don't run the command in the background, a TERM handler doesn't run until the command exits

include *.py
include */*.py
recursive-include data *.gif *.png *.ico *.css *.js
recursive-include i18n *.po
recursive-include wdoc *