New fuzzing targets and their corpus directories are not always added
to old branches, since the new features are usually not backported.
We still would like to be able to keep CI-fuzz enabled on these branches,
so we need to properly handle missing directories.
* [presubmit] Enforce language attribute in projectt.yaml to be always set.
* Update documentation, better presubmit check, new project template.
* add docstring to templates.py
* Add example values in the project.yaml template and remove python value for now
* Add "project: c++" to 256 projects
* format
* Add labels and selective_unpack sections to the presubmit check
* fix incorrect auto_ccs format in three projects
* fix nss emails after rebase
jonathanmetzman