Can now disable the keyboard layout display!

Release version 1.8.0.

Changes:

- authproto_pam: all pam_setcred.
- main: detect current Xss state at startup.
- main: wakeup on SIGUSR2.
- saver_mpv: perform playlist looping inside mpv.
- saver_multiplex: export screen saver index as XSCREENSAVER_SAVER_INDEX to
  sub-savers.
- XSECURELOCK_MULTIPLEX_BACKGROUND_COLOR: configurable background color.
- XSECURELOCK_SAVER_DELAY_MS: allow sleeping before mapping windows, for
  smoother initialization of children.
- XSECURELOCK_VIDEOS_FLAGS: flags for mpv (and also mplayer).

Release version 1.7.0.

Changes:

* Auth cursor blinking can now be disabled with `XSECURELOCK_AUTH_CURSOR_BLINK=0`.
* The white obscurer window now also shows a text indicating why the user sees it.

Release version 1.6.0.

Release version 1.5.1.

Changes:

- XSECURELOCK_FORCE_GRAB no longer sometimes fails to re-map the unmapped
  windows in case locking fails despite the forcing. Previously, a missing XSync
  call led to the re-mapping sometimes not taking effect.

Release version 1.5.0.

Changes:

- Always wake up from mouse motion events.
- Set PAM_RHOST to "localhost" as recommended by the Linux-PAM manual; add a
  feature to disable setting this field entirely as a workaround for
  pam_fprintd.
- Remove some stderr spam.
- Detect VNC and Chrome Remote Desktop servers and refuse to lock them, as
  locking them would not make much sense (can be overridden).
- Allow the helpers directory to be recreated while xsecurelock is running.
  Fixes issues like "cannot unlock after unattended package upgrade".

Changes:

- clear window when raised to workaround graphics driver issues
- Add password promt choices (hidden, asterisks, cursor, disco, emoji, ...)

Changes:

- Dimmer: run at exact specified fps, not minimum fps
- Fix packaging of run-iwyu.sh

Release version 1.3.2

Changes:
- Improve displaymarker randomness
- Minor fixes in saver_livestreams and build-release.sh

Release version 1.3.1.

Changes:
- Release process is now automated.
- Some garbage files in 1.3 (test/*.o) are no longer included.