janet: update to 1.16.0

## 1.16.0 - 2021-05-30
- Add color documentation to the `doc` macro - enable/disable with `(dyn :doc-color)`.
- Remove simpler HTML docs from distribution - use website or built-in documentation instead.
- Add compiler warnings and deprecation levels.
- Add `as-macro` to make using macros within quasiquote easier to do hygienically.
- Expose `JANET_OUT_OF_MEMORY` as part of the Janet API.
- Add `native-deps` option to `decalre-native` in `jpm`. This lets native libraries link to other
  native libraries when building with jpm.
- Remove the `tarray` module. The functionality of typed arrays will be moved to an external module
  that can be installed via `jpm`.
- Add `from-pairs` to core.
- Add `JPM_OS_WHICH` environment variable to jpm to allow changing auto-detection behavior.
- The flychecker will consider any top-level calls of functions that start with `define-` to
  be safe to execute and execute them. This allows certain patterns (like spork/path) to be
  better processed by the flychecker.

(nia)