Document HTTP rules a little better

It turns out we don't document the "port" option anywhere, so probably
worth doing a bit of an overhaul here.

 - Expand the top-level HTTP rules comment, clarifying how things are
   matched and describing each field.

 - Improve the comments on the default HTTP rule. We now also describe
   the $private rule and its motivation.

 - Don't drop/ignore invalid rules. This gets written back to the
   original config file, so is very annoying! Instead we now log an
   error and convert the rule into a "deny all" rule, which should make
   it obvious something is wrong.

projects/forge/src/generated/resources/assets/computercraft/lang/en_us.json

@@ -99,7 +99,7 @@
   "gui.computercraft.config.http.bandwidth.global_upload.tooltip": "The number of bytes which can be uploaded in a second. This is shared across all computers. (bytes/s).\nRange: > 1",
   "gui.computercraft.config.http.bandwidth.tooltip": "Limits bandwidth used by computers.",
   "gui.computercraft.config.http.enabled": "Enable the HTTP API",
-  "gui.computercraft.config.http.enabled.tooltip": "Enable the \"http\" API on Computers. This also disables the \"pastebin\" and \"wget\"\nprograms, that many users rely on. It's recommended to leave this on and use the\n\"rules\" config option to impose more fine-grained control.",
+  "gui.computercraft.config.http.enabled.tooltip": "Enable the \"http\" API on Computers. Disabling this also disables the \"pastebin\" and\n\"wget\" programs, that many users rely on. It's recommended to leave this on and use\nthe \"rules\" config option to impose more fine-grained control.",
   "gui.computercraft.config.http.max_requests": "Maximum concurrent requests",
   "gui.computercraft.config.http.max_requests.tooltip": "The number of http requests a computer can make at one time. Additional requests\nwill be queued, and sent when the running requests have finished. Set to 0 for\nunlimited.\nRange: > 0",
   "gui.computercraft.config.http.max_websockets": "Maximum concurrent websockets",
@@ -113,7 +113,7 @@
   "gui.computercraft.config.http.proxy.type": "Proxy type",
   "gui.computercraft.config.http.proxy.type.tooltip": "The type of proxy to use.\nAllowed Values: HTTP, HTTPS, SOCKS4, SOCKS5",
   "gui.computercraft.config.http.rules": "Allow/deny rules",
-  "gui.computercraft.config.http.rules.tooltip": "A list of rules which control behaviour of the \"http\" API for specific domains or\nIPs. Each rule is an item with a 'host' to match against, and a series of\nproperties. Rules are evaluated in order, meaning earlier rules override later\nones.\nThe host may be a domain name (\"pastebin.com\"), wildcard (\"*.pastebin.com\") or\nCIDR notation (\"127.0.0.0/8\").\nIf no rules, the domain is blocked.",
+  "gui.computercraft.config.http.rules.tooltip": "A list of rules which control behaviour of the \"http\" API for specific domains or\nIPs. Each rule matches against a hostname and an optional port, and then sets several\nproperties for the request.  Rules are evaluated in order, meaning earlier rules override\nlater ones.\n\nValid properties:\n - \"host\" (required): The domain or IP address this rule matches. This may be a domain name\n   (\"pastebin.com\"), wildcard (\"*.pastebin.com\") or CIDR notation (\"127.0.0.0/8\").\n - \"port\" (optional): Only match requests for a specific port, such as 80 or 443.\n\n - \"action\" (optional): Whether to allow or deny this request.\n - \"max_download\" (optional): The maximum size (in bytes) that a computer can download in this\n   request.\n - \"max_upload\" (optional): The maximum size (in bytes) that a computer can upload in a this request.\n - \"max_websocket_message\" (optional): The maximum size (in bytes) that a computer can send or\n   receive in one websocket packet.\n - \"use_proxy\" (optional): Enable use of the HTTP/SOCKS proxy if it is configured.",
   "gui.computercraft.config.http.tooltip": "Controls the HTTP API",
   "gui.computercraft.config.http.websocket_enabled": "Enable websockets",
   "gui.computercraft.config.http.websocket_enabled.tooltip": "Enable use of http websockets. This requires the \"http_enable\" option to also be true.",