Add support for renaming dond to docker.orig

Useful in case there is more than one docker wrapper, so that you can
name your original docker binary to docker.orig2, dond to docker.orig,
and then your wrapper as docker.

dond

@@ -235,6 +235,10 @@ elif [[ "${0}" == *"/docker" ]]; then
   # If this shim is named docker, then we expect the original docker to be
   # named docker.orig
   readonly docker_path="docker.orig"
+elif [[ "${0}" == *"/docker.orig" ]]; then
+  # If this shim is named docker.orig, then we expect the original docker to be
+  # named docker.orig2
+  readonly docker_path="docker.orig2"
 else
   # If this shim is not named docker, then we can simply call docker
   readonly docker_path="docker"