libgphoto2 2.5.29 release

general:
* fixes build failures of libgphoto2 frontends and builds using the
  wrong libgphoto2 headers (issue #717)

ptp2:
* fixed a regression in Fuji preview capture which would lead to crashes
* made the wait-event property extractor more robust (it sometimes gets NULL ptrs), hopefully fixing Sony crashes
* sony: fixed a crash in sony f-number
* panasonic: added more configs adjustgm, adjustab, colortemp, afmode, mfadjust, expmode, recording
* fixed some bugs caused by refactoring / memory leak fixes
* added:
  - Kodak m531
  - HP Photosmart E331
  - Nikon DSC 6

translations:
* updated polish, ukrainian, russian, serbian
* added romanian
