v2.8

This is a stable-ish release. No further breaking changes are currently
contemplated for the 2.* release series.

Breaking changes:

• bashy-node: Reworked build options to use the newly-standardized multi-value
  forms. Only nominally breaking in that use of bashy-node at all is
  pretty minimal.

Other notable changes:

• bashy-basics:
  • New utility functions env-clean, env-minimize, and env-names.
  • New helper library buildy-help, to help avoid some project-build-related
    boilerplate.