(cua--deactivate-rectangle): Don't deactivate the mark.
(cua-set-rectangle-mark): Don't set mark-active since
cua--activate-rectangle already does it for us.
(cua--rectangle-highlight-for-redisplay): Unhighlight a previous
non-rectangular region.
* lisp/emulation/cua-base.el (cua-repeat-replace-region):
Use with-current-buffer.
* lisp/net/gnutls.el: Use cl-lib.
(gnutls-negotiate): `mapcan' -> cl-mapcan.