Creator allows creating of new CMake project although no CMake is available

1. Make sure that you don't have a cmake binary in your environment.
2. Start Creator with empty settings, e.g. by passing the parameter -settingspath.
3. Start creating a new project using "File" -> "New File or Project..." -> "Non-Qt Project" -> "Plain C++ Application".
4. On the "Define Build System" page, select CMake.
5. On the "Kit Selection" page, select the automatically created default kit "Desktop".
   Creator will give you a useless project. You can neither compile it, nor add files. Creator can not even open it properly.

Creator should refuse to use a kit without a CMake binary for a CMake project. For qmake projects and kits without a Qt version, this works correctly.