Clusterfuzz

- Various bug fixes.

- Various bug fixes.

- Python 3 migration is complete.
- Added Peach mutation strategy for engine fuzzers.
- Added support for Google Cloud IAP authentication.
- Added stop gaps to prevent corpus explosion (e.g. corpus element must be less than 5 MB).
- Use ANTLR grammar for tokenization during testcase minimization (html, js).
- Store statistics on corpus cross-pollination during corpus pruning.
- Removed dependency on Google App Engine SDK.
- Removed unused Go code.
- Various bug fixes.

- Added an uploader permission type to allow certain users to upload to any job/fuzzer.
- More Python 3 conversion changes.
- Bumped up libFuzzer rss limit to 2.5GB.
- Various bug fixes.

- Various bug fixes.

- Better crash type reporting on various UBSan issues.
- Initial support for Honggfuzz.
- Additional fixes in preparation for migration to Python 3.
- Migrated off deprecated App Engine Memcache to Cloud MemoryStore for Redis.
- Added libFuzzer fuzzing support for Android (using HWASan).
- Automatically correct certain common mistakes in dictionaries.
- Various bug fixes.