Support for parameters

[grtjn]

Allow entering of parameters through queue manager and api, storing them with preservation of data-type. (using a map:map for instance)

[grtjn]

Partly solved. You can pass parameters through the create-task API call now as a map:map. The map:map is passed around upto the execution moment, so data-types should be preserved. The little queue GUI doesn't support entering params yet, but it might be difficult to specify type anyhow..