Copy as HTML function: set external clipboard correctly
Choose CLIPBOARD rather than PRIMARY as Emacs clipboard type to
reach the NS Pasteboard.
cua--region-keymap: remap additional enter key function as to respect `overwrite-mode'
remap `org-return' (used by `org-mode) and
`reindent-then-newline-and-indent' (used by `enriched-mode') to facilitate
replacing the region in `cua-mode' (see also `override-mode').
Fix "OS X" dictionary lookup via context menu