[Optional extension proposal] Instance handling

[jcelerier]

I propose the following requests to allow a client to request the creation of a new node to the server (which the server is absolutely not forced to accept, or even react to).

server:1234/my/video?ADD_NODE=its_name&OPTIONAL_ATTRIBUTE_1=...&VALUE=...&...

The server may then reply with a PATH_CHANGED (or PATH_ADDED, if the server supports it ?) if something was added.

This is useful for instance if you want to add new media, etc... from client applications.

And the second request :

server:1234/my/video?REMOVE_NODE=its_name

with self-explaining semantics.