problems compiling 4.8 on system with both qt4 and qt5

[Jack Ostroff]

I think this is at least part of my problem trying to build from 4.8 
branch on both my home Gentoo system and a VirtualBox Kubuntu 16.10.  I 
know I have enough of qt5 installed, as I have successfully compiled 
from git head.  I'm pretty sure I have enough of qt4 installed, but it 
seems that the qt5 stuff is found in preference to the qt4.  I got the 
cmake to complete successfully by first doing EXPORT QT_SELECT=4. 
However, when I then do "make" it fails with a complaint about a moc 
file being compiled with 5.6.1. when it should be 4.8.7.  I'm hoping 
there is some other environment variable I should set before doing the 
cmake, or perhaps something I can add to one of the CMake files.

Thanks for any suggestions.

Jack