2538.Newandimproved

The :meth:req.get_param_as_list <falcon.Request.get_param_as_list> method now supports a new argument, delimiter, for splitting of values. In line with the OpenAPI v3 parameter specification, the supported delimiters currently include the 'pipeDelimited' and 'spaceDelimited' symbolic constants, as well as the literal ',', '|', and ' ' characters.