(smerge-basic-map): Rename from smerge-basic-keymap. Change the bindings for smerge-diff-*. (smerge-*-map): Use easy-mmode-defmap. (smerge-(next|prev)): Use easy-mmode-define-navigation. (smerge-keep-*): Use smerge-auto-leave.
diff3-style conflict markers, such as generated by RCS