libgphoto2 2.5.23 release

ptp2:
* Sony capture stability and speed improvements
* Canon EOS capture stability improvements, reduce partial read blobs from 5MB to 1MB
* Canon EOS M image format unpacking adjustments
* Olympus OMD: bulb capture added, trigger capture capable
* Panasonic GH5: added manualfocusdrive, capturetarget
* Canon PowerShot X work ... trying to support / improve stability of capture
* PTP string packing adjusted to standard (empty and null strings)
* New ids added:
  * Sony Alpha A68, RX100M6, DSC-WX350
  * Nikon Coolpix L100
  * Canon PowerShot G7X, G9X Mark II
  * Canon Rebel T6, EOS 2000D
  * Fuji X-A2, GFX 50R, XT-30
  * Ricoh WG-M2
* libmtp ids synced.

pentax:
* synced smaller parts with pktriggercord

translations:
* updated danish

fuzzing:
* vusb and sample-afl now able to fuzz all USB cameras (even if slow)

all:
* Various crashes fixed that were found during AFL fuzzing the USB drivers

* The camlibs for cameras (and driver) older than 15 years have been
  default disabled for installation, to speed up libgphoto2 startup
  and also reduce attack surface against malicious USB devices.

  See OUTDATED.txt in git for notes.

  You can reenable them using:

	./configure --with-camlibs=all,outdated

  or by the camlib driver name (sample: jd11):

	./configure --with-camlibs=all,jd11

  To get the lists of all camera libraries use:

	./configure --help

  If you still have an old camera using one of these camlibs in active
  use, please report this to the devteam so we can reenable it per
  default.

