revamp the autostart functionality, so autostart apps launch after openbox.

revamp the autostart functionality, so autostart apps launch after openbox.

add /usr/libexec/openbox-autostart which runs the global/user scripts and
  launches /usr/libexec/openbox-xdg-autostart (which runs .desktop autostart
  stuff)

make openbox-session call openbox with --startup option, to make openbox launch
  /usr/libexec/openbox-autostart *after* it is initialized.

add /etc/xdg/openbox/environment and ~/.config/openbox/environment files to let
  user change environment variables (locale) for their Openbox session, which
  openbox-session loads before running openbox.