Set commands.c's merge driver to binary so when it conflicts during a merge git will leave the local version unmodified.
This way our Makefile will rebuild it based on src/commands/*.json before trying to compile it.
Otherwise the file gets modified with merge conflict markers and gets the same timestamp as the *.json files,
so the Makefile doesn't attempt to rebuild it before compiling and we get a compilation error.
yoav-steinberg