Started writing the schema to represent validation rules
The first version of json export
Added a bunch of constructors.
Added a name transformer utility that ... wait for it ... lets you transform names.
JsonIo now writes things with string names. This is mediated through a NameTransformer from QName to String.
First semi-functional implementation of JSON reading. It misses some of the input at the moment.
Json output now round-trips.
Merge branch 'feature/jsonio' into develop
This provides a json serialisation for the Datatree syntax.
Merging conflicts
Merge branch 'develop' into feature/schema
Changes the sbol terms in the example
Added curly brackets for QName serialisation
Added schemas for core, sequence and instantiation classes
Added the SchemaCatalog class
Adding stuff we embarasingly  missed off for the graphviz support.
Merged the schema branch
Removed auto-generated app class.
Graphviz exporter now has links for references between documents, and a simple stylesheet language.