libgphoto2 2.5.28 release

general:
* OS/2 support removed (broken and unused since at least 2006)
* remove built-in rpm packaging (use distro packaging instead)
* remove linux-hotplug rule creation (removed from distros around 2006)
* remaining text which was iso-8859 is UTF-8 now (except one po file)
* To override docdir and htmldir, use configure arguments --docdir=
  and --htmldir= instead of --with-doc-dir= and --with-html-dir=
* some code cleanups, especially handling of include files and i18n handling

ptp2:
* wait event
  * property changes now reported with "'name' to 'value'" added
  * object info changes now reported as FILE_CHANGED events (e.g. if you change protection flags)
* Nikon J1: capture fixed
* Olympus: fixed that wait time was twice as long as required if no events arrived
* Sigma Fp: added basic beta support for capture, live view and config.
* Sony:
  * mark all widgets as read-write again, read-only logic was not 100% correct
  * speed-ups and fixes to the stepping based config setting
* Canon EOS
  * handle newer EOS R series reporting of configs (ISO, Aperture, Shutterspeed)
  * track UI lock state to avoid device busy reports
  * fixed "zoom" range settings (for lenses with powered zoom, also for today Powershot)
* Fuji:
  * ptpip improvements
  * bug fixes
  * some Fuji cameras have now liveview only for webcam (need new firmware)
* various small fixes and code cleanups
* New ids:
  * Sony Alpha-RX1R II, ILCE-7C, ZV-E10, A6600, DSC HX-80, ILCE-7RM3A, ILCE-7RM4A, DSC-A7S III
  * Nikon Coolpix B500, Zfc
  * Canon EOS M50m2, Digital IXUS 132
  * Fuji X-Pro3, GFX 100S, X100V

canon:
* fixed wait event crashes
* correctly mark read only config widgets as read-only

pentax:
* fix PEF raw files for non-K100D

translations:
* updated german, french, polish, ukrainian
