incorporation of netrc security patch

Along with general debugging of the installation setup, I've incorporated the netrc security patch which requires certain permissions on the netrc file used.

We should note that the current version of lvalert (lvalert@46d4dfde) is incompatible with the version of Python's netrc package currently installed on CIT (lvalert expects netrc._parse to accept 4 arguments whereas the version installed on CIT only accepts 3). Beyond this minor complication (which should be fixed with modifications within lvalert alone and an updated version deployed before lvalert-heartbeat is), the code should be ready for deployment.