Allowed optional parameters in query string

When initializing, added the option urlParams which is an object
contaning name,value pairs like {"excludeIDs":getExcludedIDs,"const":1}.
This is added to the search query string. Would result in something like

http://localhost:52854/Admin/searchForSwimmers?excludeIDs=1&const=1&q=luk

The initialzation was:

$("#swimmerAddingDropdown").tokenInput("/Admin/searchForSwimmers", {
urlParams: {"excludeIDs":getCurrentSwimmerList,"const":1},

etc...