* Add support for sm- prefixed builds
* Add support for fuzzilli builds
* Add typing hints to all functions
* Use an enum for build search order
* Support pathlib consistently (all APIs should take path/str)
* Add support for no-opt builds
* Check that all artifacts exist before any are downloaded
* Add support for fetching multiple targets (eg. `--target firefox js gtest common`)
* Drop support for Python 3.5