Stable document format: - Infrastructure for migrating old to new formats - Separate structure for storing the document, decoupled from the `struct DocumentMessageHandler` and `struct NodeNetwork` definitions - One struct per version, plus an associated upgrade function that goes to the next version - ASCII graph structure markup format (use RON syntax, we need to define the semantics), see #1605 - Translation back from the ASCII format to those structs - A way to look up a built-in node's definition by its name and not have to store its sub-network - A way to store user-created subgraph network (or modified from a built-in node definition)
Stable document format:
struct DocumentMessageHandlerandstruct NodeNetworkdefinitions