Trigger an error on unrecognized properties

[dgutson]

I spent a long time trying to find the reason why sequence diagrams were not shown.
It turned out that there was this line in the changelog that I missed:

Renamed plantuml.sequenceDiagrams to plantuml.sequenceDiagram

I propose to throw an error on unrecognized properties. This would had help me to avoid wasting so much time. Likewise for typos.

[simonbrowndotje]

Unfortunately this isn't really viable, given that people might be using their own properties (example).

[dgutson]

In that case, what about "declaring" non-standard properties?

declare {
    property name "description"
}

This would also help documentation for users and prevent typos, help to detect breaking changes such as sequenceDiagram/s.

[dgutson]

Moreover, there could be a property force.declare.properties to control this behavior.

[simonbrowndotje]

If you'd like to perform further validation on your workspace, I'd recommend writing a DSL plugin to do this.