Displaying why one schema isn't a subset of another

[crdoconnor]

Is it straightforward to provide a list of fields which invalidate one schema being a subset of another? - i.e. debugging information

Currently if you use this to validate schema compatibility, it does give a yes/no answer but it doesn't provide any context. In large schemas, you would have to manually dig around to figure out what broke.

This may be a large chunk of work and I'd understand if you didn't want to do it. I'm thinking of forking and and providing this functionality in a separate project along with #24, but I thought I'd drop a note here first just in case these were features that you were considering.

[hirzel]

If you want to consider contributing better error reporting, we would welcome that!