[CMake] FindQt.cmake for Qt4

[John Biddiscombe]

>>MESSAGE("Find Qt has been deprecated and you should use FindQt3 or
>>FindQt4 depending upon your needs")
>>INCLUDE(FindQt3)
>>    
>>
>It's better keep the current FindQt with the same name, otherwise the users 
>have to change their projects to use FindQt3 instead of FindQt.
>  
>
I don't understand the problem. Using the above, it will still work with 
FindQt, but will show a deprecation warning and then load FindQt3