Fix mangling python shebangs
    
    - use pathfix.py instead of sed
    - clean up '*~' files
    
    Fixes:
    policycoreutils has broken dependencies in the rawhide tree:
    On i386:
            python2-policycoreutils-2.7-11.fc28.i686 requires /usr/bin/python22
    On armhfp:
            python2-policycoreutils-2.7-11.fc28.armv7hl requires /usr/bin/python22