Add support for a host and port which are set at runtime

Using grunt's template syntax to resolve portions of a host which are not set when the config is processed results in the host being resolved with empty values. When that happens Phantom won't start.

More specifically, when the host is configured to get the hostname and port from connect (`http://<% connect.test.options.host %>:<% connect.test.options.port %>/`) and connect is configured to generate the host and port dynamically with `?` and `*`, the host will not resolve properly even though connect sets the values in the config: `http://:/`.

This commit adds the runtimeHost and runtimePort options, which will look up the specified value and resolve the host properly.

It also adds a fix for debugging the options, which were being logged as [object Object] instead of the actual options.