Log Message:
gash: Update to 0.3.0

Changelog:

Noteworthy changes in release 0.3.0 (2022-02-11)
================================================

New features

  - Arithmetic expansion.
  - Simple asynchronous commands.
  - A language specification is now provided, allowing you to use the
    evaluator from the Guile REPL by typing ",L sh".
  - Redirects now honor the 'noclobber' option.
  - The 'wait' built-in.
  - The 'umask' built-in can now display the current umask.

Bug fixes

  - An empty command will now reset the status.
  - The 'read-sh' procedure now reads from 'current-input-port' by
    default (before it used 'current-output-port').

Miscellaneous improvements

  - Various performance improvements.
  - Word expansion has been split into two steps, paving the way for a
    compiler.
  - Guile 3.0 is now explicitly supported.