Fix static linking on Windows
Fix static linking on Windows

CMake can mistakenly think that installed Qt4 is shared and add
-DQT_DLL to QT_DEFINITIONS. Need to be sure that with static QJson
will be used static Qt4.

coolshou/qjson,coolshou/qjson,flavio/qjson,drizt/qjson,drizt/qjson,flavio/qjson