Breaking changes:
- Remove function `b64decode`, use `b64dec`
- Remove function `b64encode`, use `b64enc`
- Remove default from `env`, use `env "MYVAR" | default "..."`
- Remove function `hash`, use `sha1sum` / `sha256sum` / `sha512sum`
- Function `now` returns `time.Time`, use `now | date "[format]"`
- Function `split` now has reversed parameters `split <sep> <str>`
Signed-off-by: Knut Ahlers <knut@ahlers.me>