Add -codesign option.

Use the "codesign" tool with the provided signing identity to
sign all code binaries in the bundle. Application code binaries
include the app executable(s), plugin and framework/dylib
dependencies.

Finally, run "codesign --verify" to verify that the app
bundle is correctly signed.

Change-Id: Idfff030a2b218e1dc1ad1bc279a32a330665b347
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>