Publish supported features matrix for all clients

This is an improvement request.

My first adventure into Swagger and I'm finding massive inconsistencies between the different language implementations. What makes this extremely frustrating is that the code generator will generate stuff that isn't actually functional. For example, the Java client generator doesn't support inheritance. It happily generates a useless class instead. Objective-C supports inheritance but it doesn't support enums. Again, it will happily generate useless placeholders for the enums that have no data and break the client.

I'm finding this by trial and error by manually writing tests (the tests generated by swagger-codegen are pretty much useless without some way to specify sample input values)

It would have saved me loads of time if there was a supported feature matrix that showed which features are supported by each client and suggested workarounds. I will happily contribute to this matrix.

Start by inventorying the language implementations and the generator behavior described in the issue, including Java inheritance and Objective-C enums. Use manually written tests with sample input values to verify each feature. Done means a supported feature matrix covers all clients and records useful workarounds.