[vte] (6 commits) Non-fast-forward update to branch wip/systemd

[Christian Persch <chpe src gnome org>]

The branch 'wip/systemd' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  62c0927... lib: Add smart pointer for g_free()able things
  829754a... pty: Document VTE_SPAWN_NO_PARENT_ENVV
  8b504ec... systemd: Add systemd support
  beed495... systemd: Install config drop-in for vte-spawn-.scope
  9f22655... systemd: Add option to disable systemd support

Commits added to the branch:

  2780439... lib: Add smart pointer for g_free()able things (*)
  427eebb... pty: Document VTE_SPAWN_NO_PARENT_ENVV (*)
  1d48896... systemd: Add systemd support (*)
  9e8168d... systemd: Install config drop-in for vte-spawn-.scope (*)
  1ea1c04... systemd: Put child process into the parent's slice (*)
  cc557aa... systemd: Add option to disable systemd support

(*) This commit already existed in another branch; no separate mail sent