[KPhotoAlbum] Marble versioning

[Harald Barth]

> The Marble guys should rethink their versioning :-(

Ok, let's counter this with yet more ugly code, something along this
line would work for some years:

set(ALLVERS "24.0.0" "23.0.0" "22.0.0" "21.0.0" "0.28.0")
foreach(V IN LISTS ALLVERS)
 find_package(Marble ${V})
 if (${Marble_VERSION} MATCHES "[02].*\..*") )
   break()
 endif()
endforeach()
find_package(Marble ${Marble_VERSION} REQUIRED) 

will probably find the newest package for some years to come.

Harald.