google-java-format-diff.py is unusable without rolling your own wrapper script

google-java-format-diff.py assumes there is an executable in $PATH named "google-java-format", which is not part of any published releases. The basic instructions say to run with "java -jar", so to make this work, someone has to write a wrapper script. I am capable of rolling my own but it really seems like this should be part of the distribution.
