feature request: load from json

[sparr]

I would like to be able to load from the intermediate representation of a json string, rather than a native blueprint string. My use case is to make a repository of blueprint json files that can be collaboratively developed and improved.

[ericmburgess]

For now, you can do:bp=Blueprint(version_byte, json.loads(json_string))

It should have something nicer in the future, maybe auto-detection between a blueprint string, a JSON string, or nested data.

I'll probably take the version byte out of the constructor or at least make it optional, too.