Remove more XEmacs compat code from viper-*.el

Remove more XEmacs compat code from viper-*.el

* lisp/emulation/viper-cmd.el (viper-submit-report):
* lisp/emulation/viper-init.el (viper-set-insert-cursor-type)
(viper-restore-cursor-type, viper-use-replace-region-delimiters)
(viper-has-face-support-p, viper-window-display-p)
(viper-color-display-p, viper-device-type):
* lisp/emulation/viper-mous.el (viper-mouse-click-search-word)
(viper-mouse-click-insert-word, viper-mouse-click-get-word)
(viper-mouse-click-posn, viper-mouse-click-window):
* lisp/emulation/viper-util.el (viper-abbreviate-file-name)
(viper-set-replace-overlay, viper-maybe-checkout): Remove XEmacs
compat code.