Encode and decode the Base64-encoded VLQ encoding. Note that there are several variants of VLQ. This only implements the variant used by source maps.
Licensed under either of
at your option.
See CONTRIBUTING.md for hacking.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.