Adding support of dictionaries in tool options section

[Annrtl]

Using dictionaries as tool options

[olofk]

Thank you. I totally see the idea. There are two problems unfortunately. First, we recently rewrote the whole core parsing code to be based on jsonschema instead, so this will not apply anymore. But the other thing is that I'm reluctant to add more features now to the old tool API and would prefer all development effort to be directed to features in the flow API instead, so I will reject this patch. Happy to discuss such a feature for the flow API though