A new setting to override the IP address auto-detection.

This can be used as workaround if the autodetection of the hosts IP
address does not work. If this is set, the autodetection will not be
attempted.
Fix for detection of a machines IP address.

In Ruby the assignment operator has a higher precedence than the "or" operator. In this particular use case the "||" operator should be used instead to achieve the intended effect.
Merge pull request #37 from amfranz/override_host_ip

A new setting to override the IP address auto-detection.