* [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
* Add libxls
* Add fuzzing target for libxls
The library parses only one format, so only one fuzzer (fuzz_xls) is
included. The initial test corpus includes ~30 files. Tested locally
on Linux.
Oliver Chang