Log Message:
(math/R-gss) Updated 2.2.3 to 2.2.4

Tue 14 Mar 2023 08:36:01 PM EDT, Chong Gu  <chong@purdue.edu>

	* DESCRIPTION: Version 2.2-4.

	* inst: edited CITATION to conform with new standard.

	* R: Edited numerous functions to replace "class(obj)==string" by
	"inherits(obj,string)".

	* src: Edits in smolyak.c to fix init(void), coeff(void).