modified Catalog model to lookup its configured attriutes
updated Template model for task 4 support, now supports retrieving its own attributes
added TaskServer model
implemented run model that supports task 2/3 and 4+, updated submission model to check template to see which type of runs to retrieve, updated task and task message models to support task 4 json format as well as simple entries
updated to properly encode url for calls to task api
implemented strategy in ArsBase for including fields that might not be on all servers for different versions of request
updated Submission model to implement additional fields option