A few fixes to configuring Failnozzle

Hey Lucas,

I just finished setting up Failnozzle, and found a few little issues:

- import_config_file (which is how you get settings in to failnozzle without cloning it) wasn't working for me, so I rewrote it to use the imp module (rather than execfile)
 - the list of email recipients was defined at module scope, before import_config_file had run, so overriding those settings didn't work; I changed it to defer those calls

Let me know if there's anything you'd change!