Allow disabling additionalProperties generation with a global config option

[jfarcand]

Assume you work with an existing set of JSON files that you can't modify. If you be useful to be able to set

<additionalProperties>false</additionalProperties>

in pom.xml so the Java Object is generated without additionalProperties and without the needs to change the original JSON.

[joelittlejohn]

Thanks for raising this. It sounds like a really simple change, I don't see a problem with including this.

[jfarcand]

@joelittlejohn That would make it super simple to automate something like

JSON Feeds => jsonschema2pojo => Java Object => Cassandra Mapper => Save to Cassandra

Right now the Datasax's Cassandra driver complains about

Exception in thread "main" java.lang.IllegalArgumentException: Cannot find matching getter and setter for field 'additionalProperties'
    at com.datastax.driver.mapping.ReflectionMapper$ReflectionFactory.createColumnMapper(ReflectionMapper.java:230)
    at com.datastax.driver.mapping.AnnotationParser.convert(AnnotationParser.java:160)

Thanks for the fast answer!

[joelittlejohn]

Another benefit of doing this: at present if you use source type 'JSON' there's no way to indicate that you want to disable additional properties, so it's not possible to turn them off. With this change they could at least be turned off globally.