Update to 2.2.3

Upstream changes:
Tue Aug  3 20:32:06 EDT 2021, Chong Gu  <chong@purdue.edu>

* DESCRIPTION: Version 2.2-3.

* R: Edited sscomp.

* src: Edits in smolyak.c to comment out unused calccoeff2.

Tue May 26 00:21:21 EDT 2020, Chong Gu  <chong@purdue.edu>

* DESCRIPTION: Version 2.2-2.

* R: Added sscomp and sscomp2.

* man: Added documentation for sscomp and sscomp2.

Sat May 16 15:49:33 EDT 2020, Chong Gu  <chong@purdue.edu>

* DESCRIPTION: Version 2.2-1.

* R: Bug fixes, code cleanings in numerous places.

Sun May  3 14:34:28 EDT 2020, Chong Gu  <chong@purdue.edu>

* DESCRIPTION: Version 2.2-0.

* R: i) Reworked the gssanova, gssanova1, and gssanova0 suites, to
add support for the "polr" family.  ii) Added predict9.gssanova
for response scale prediction.

* data: Added wesdr1.

* man: Updated to reflect changes in R and data.

Sat Feb 29 10:50:40 EST 2020, Chong Gu  <chong@stat.purdue.edu>

* DESCRIPTION: Version 2.1-12

* src: Bug fix in copu2newton, thanks to Elliott Sales de Andrade.

Fri Feb 28 19:40:49 EST 2020, Chong Gu  <chong@stat.purdue.edu>

* DESCRIPTION: Version 2.1-11.

Edits in R/ and man/ to prepare for the coming default
data.frame(...,stringsAsFactors=FALSE).

Merged gsscopu package into this one, adding sscopu/sscopu2 suites
for copula density estimation, and sshzd2d/sshzd2d1 suites for 2-D
hazard estimation.

(wen)