Includes some fixes from Albert:
* kscreen cmake fixes
Don't make libkscreen mandatory, give the proper version we need
* Fix the @since
* Kill Resolution and use a QSizeF
I first thought QSizeF didn't make sense, but well what's a dpi if not a number of pixels in width and some others in height?
* Remove unwanted const
* Remove unneeded utils.h includes
* Fix comments on realDPIXY()
* Make it compile in non X11
REVIEW: 111829
create again the options to force the DRM (give -DOKULAR_FORCE_DRM=ON to cmake)
KPDF_FORCE_DRM -> OKULAR_FORCE_DRM
svn path=/branches/work/kde4/playground/graphics/okular/; revision=542815