As discussed over the call on the 11th of January:
Adds functionality to define the NGINX_HELPER_LOG constant in the wp-config file to enable the logging feature.
Users who are already using the nginx-helper plugin with Enable Logging will not be affected, but if they disable the logging then they need to define the NGINX_HELPER_LOG constant to enable the logging feature again.
As discussed over the call on the 11th of January:
Ref: https://github.com/rtCamp/labs/issues/177