(zmacs-region-stays): No need to define for compiler.

(zmacs-region-stays): No need to define for compiler.

Expand all viper-cond-compile-for-xemacs-or-emacs calls to a featurep test.

Replace obselete frame-local variables with frame-parameters.
(viper-insert-state-post-command-sentinel, viper-R-state-post-command-sentinel)
(viper-replace-state-post-command-sentinel, viper-change-state-to-insert)
(viper-change-state-to-emacs): Use viper-frame-value for
viper-replace-overlay-cursor-color, viper-emacs-state-cursor-color,
viper-insert-state-cursor-color, and viper-vi-state-cursor-color values.