Schema validation - don't warn about camelCase -> camel-case params

[ewels]

Nextflow has some odd behaviour with camelCase parameters: nextflow-io/nextflow#2061

At the moment the schema validation throws warnings about unexpected params here. We should add some custom code to check unexpected params for their camelCase equivalents and not warn if found.

[ewels]

Now fixed in Nextflow, but I think it's still worth adding code to handle this as will be around in existing versions for quite some time yet.