add catchall system & http pc server

- define a catchall name to run globally or per service
- catchall must be javascript, but not necessarily a .js file
- catchall can request async mode
- catchall will catch any non-existing requests under its directory
- see wtv-flashrom:/content/content-serve.js as an example, which will catch wtv-flashrom:/content/ URLs.

- http pc: sends HTTP/1.0 to PC clients
- can be disabled with `pc_server_hidden_service_enabled`: false
- can change servicevault path by changing string of pc_server_hidden_service
- get.js in default PC service vault to get any WTV Url on the service

user_config_README.md

@@ -22,6 +22,10 @@ If you would like to see debug information about realtime bytes received from a
 		"allow_guests":  false
 ```
 If you would like to require registration, disabling guest mode, you can set `allow_guests` to `false`. Default is `true`;
+```
+		"pc_server_hidden_service": false
+```
+Set this option to false to disable the HTTP Server for Browsers. Set it to a string to use that directory under the service vaults.
 ```
 		"post_percentages": [ 0, 25, 50, 100]
 ```