1.1.5 -> 1.1.6
  * added reqdeny / reqallow rules
  * added HTTP 400 and 403 responses
  * chain regex in a list
  * reply 502 when no server is available
1.1.6 -> 1.1.7
  - implement global logging
  - have a single log function
  - handle parametrable HTTP health-checks replies
  - differentiate http headers and http uris
  - log http requests on demand, and destination server IP
  - add x-forwarded-for