* lisp/delsel.el (delete-selection-local-mode): Add local version of
'delete-selection-mode'. The local mode sets the value of the variable
'delete-selection-mode' to maintain compatibility with packages and
features that consider the existing mode.
* doc/emacs/mark.texi (Using Region): Describe
'delete-selection-local-mode'.
* etc/NEWS: Describe 'delete-selection-local-mode'.
e0b21b6c4d