[aur-general] Transition users from package x to package y (package x deprecated)

[Michael Kogan]

Done, thanks! Eventually I did all of the above (a "replaces" field in the
new package which seems to have no impact though, an echo output with the
deprecation message, a deprecation message in the package description, a
comment on the AUR page and an out of date notification with again a
deprecation message). Let's see how it goes! :)