add repack.d/common.sh: move dist-packages to site-packages for python modules in /usr/lib

repack.d/common.sh

+#!/bin/sh -x
+# It will run with two args: buildroot spec
+BUILDROOT="$1"
+SPEC="$2"
+
+for i in lib/python3 lib/python2.7 ; do
+    t=$i
+    if [ -d $BUILDROOT/usr/$i/dist-packages ] ; then
+        mv -v $BUILDROOT/usr/$i/dist-packages $BUILDROOT/usr/$t/site-packages
+        subst "s|/usr/$i/dist-packages|/usr/$t/site-packages|" $SPEC
+    fi
+done