Issue #529 - Added url key value pairs to test and page responders.
Issue 529 - Gave URL params precedence over markup variables.
Issue #529 - Kept SystemVariableSource immutable. Passed request to ParsingPage.
Issue #529 - Passed UrlVariableSource to ParsingPage so no urlParams field.
Issue #529 - Cleaned up unused Java imports.
Merge pull request #531 from mwarhaftig/master

Feature #529 - Allow Markup Variables In Test & Page Responder Urls
Remove UrlPathVariableSource dependency from ParsingPage.