Make osx-app.sh a configured file and remove Autotools targets.

Make osx-app.sh a configured file and remove Autotools targets.

Rename osx-app.sh to osx-app.sh.in and add the version to the plugin
path at configure time.

Instead up updating Autotools accordingly just remove the macOS
packaging targets. gf61c381b5a removed support for Autotools in
osx-app.sh and if anyone wants to build macOS packages I'd prefer that
they use the same toolchain as the buildbot.

Change-Id: Ide5205265bf8859a85b1afab68fa8f8285952bd3
Reviewed-on: https://code.wireshark.org/review/23839
Reviewed-by: Anders Broman <a.broman58@gmail.com>