protect shell variables in ifcfg files, for lines like
-rw-r--r-- 5675 modprobe.py
-rwxr-xr-x 17017 plnet.py
-rw-r--r-- 2643 pyplnet.spec
-rw-r--r-- 1546 setup.py
-rw-r--r-- 1970 sioc.py