smart scan replacement feature

[jiyoo]

Feature request for a command that is a combination of cua-repeat-replace-region (M-v) from CUA mode and smartscan-symbol-go-forward (M-n) from smart-scan.

When one uses cua-repeat-replace-region to replace hello with hi, it ends up replacing hello in ohello or helloo as well. On the other hand, the new command should replace just those parts that smart-scan would get to.

At the conservative side, one could provide a command not bound to any key by default that works only when CUA mode is enabled. At the forcing side, the command may be bound to a key in smart-scan mode map by default, depending on a user option.