Use realpath() to resolve our program file directory on macOS. This lets
us create symlinks to the program files in our application bundle
without affecting our plugin and other paths.
Change-Id: If77cbd7da56e01f2cd602334d361c8aa52afeae0
Reviewed-on: https://code.wireshark.org/review/33151
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Reviewed-by: Gerald Combs <gerald@wireshark.org>