Few fixes for Debian packaging

Here a few cleanup for Debian packaging.

Some thoughs:

 - We shouldn't have two different upstart definitions. I am in favor of removing the one outside the debian/ directory. However, it is not strictly equivalent. I would prefer to use a directory instead of a config file like in the original upstart job. I let the original submitter fix that if he agrees (cc @derpston)

 - The provided configuration file is not generic. I think this is useless to ship a configuration file that won't work (on hosts without `eth0` for example). We should remove the `interface` keyword. Maube just keep `log_level` which is the only decision we can make for the user.

I will provide an init script for Debian in a seperate pull request (only Ubuntu uses upstart by default). The init script provided in `ops-misc` is only compatible with Redhat.