libqjson's cmake support

[David Faure]

kdeutils/ark/kerfuffle doesn't compile with unittests enabled, because it can't 
find the qjson library.

The issue is:

* qjson.git generates a qjson-config.cmake which sets qjson_LIBRARIES
  (lowercase because the cmake project name is qjson)

* qjson.git also installs a FindQJSON.cmake (!! wrong, a lib shouldn't install 
its own find module, but that's another topic !!), which looks for
  QJSON_LIBRARIES (uppercase)

* kdeutils/ark/kerfuffle/tests/CMakeLists.txt also looks for QJSON_LIBRARIES 
uppercase [and seems to find qjson-config directly, without going through 
FindQJSON.cmake, if I read strace properly]

-- 
David Faure, faure at kde.org, http://www.davidfaure.fr
Sponsored by Nokia to work on KDE, incl. Konqueror (http://www.konqueror.org).