mod_http: Use RFC 7239 Forwarded header to find original client IP Prefer over X-Forwarded-* since it has an actual specification. Main practical difference is that Forwarded may carry more properties than only the IP address since it is a structured header. Since we parse it into an array, it is easier to do the logical thing and iterate backwards trough proxies until an untrusted one is encountered. Compare the handling of X-Forwarded-For. The 'secure' field now accounts for the full chain of proxies, which must be secure all the way to be considered secure.

mod_http: Handle bracketed IP address format from RFC 7239 There are hints that this format might be used in X-Forwarded-For as well, so best handle it everywhere. Strips both brackets and optional port number.

util.http: Implement parser for RFC 7239 Forwarded header Standardized and structured replacement for the X-Forwarded-For, X-Forwarded-Proto set of headers. Notably, this allows per-hop protocol information, unlike X-Forwarded-Proto which is always a single value for some reason.

util.set: Remove duplicate __freeze metamethod Backs out 895a82c5d8d4 beacuse __freeze already added in a96a2fbcc6c0

Merge 0.12->trunk

util.prosodyctl.check: Fix error where hostname can't be turned into A label Where gethostname or tohostname returns an invalid name, e.g. containing underscores or something, to_ascii would reject this and return nil, which triggers an error in the dns lookup. Reported by prova2 in the chat, for whom tohostname returned a long name containing underscores.

util.startup: Record current version in a metric Useful to have this info available when juggling metrics, e.g. to see if things changed between versions.

util.startup: Remove componentmanager backwards compatibility Module was removed in 0.8.0 in c52b06de9b27

net.http.server: Return request ID in header to aid debugging Eases locating the request in logs

mod_admin_shell: Show internal URL where different from external