Eric Seidelpatch command line tool
This is the tool used by the shorebird command line to compute the patch
file for uploading to the server.
This currently uses the rust bidiff crate to compute the patch file.
and could just use the bic command line tool included in that crate. However
we're explicitly writing our own command line to allow us to change the
underlying compression without affecting the shorebird command line callers.
Usage
patch <old> <new> <patch>