The following PRs/issues have not been fully adopted or parts have been overlooked. The following PR tries to fix this.

• Complete: option enable_natpmp => enable_pcp_pmp 02da705
  Remove old name still present in documentation/comments
• Complete: upnpc: Revise help/usage #681
  Fix partial help rewrite (remove "redirect", currently more confusing). Add note about optional IGDv2 commands and IPv4/IPv6. Minor wording update/normalise, reduce line width/breaks.
• Complete: miniupnpd: SSDP search response cache-control header, no UPnP UDA 1.0 compliance #698
  Comment notify_interval in configuration, as same value as default and fix help.
• Complete: miniupnpd: Add daemon version to XML (child) device descriptions #709
  Empty dummy values from advertised informal serialNumber and UPC as IMHO it looks unfinished/unclean not like a long existing project. Remove the change in the root device modelDescription to keep the root device white labelled as before.
• Complete: Fix/standardise SOAP/HTTP headers #745
  Remove the Cache-Control: no-cache header as it is not used in the IGD specification and by other clients and test tool. Only used in HTTP when using a cache/proxy, which is not possible with IGD. Normally only used in HTTP for GET and not for POST, but in miniupnpc only for POST and not for GET requests. No routers known to need this.