refactor: refill optspec at 78 columns.

* lib/specl/main.lua (optspec): Refill at 78 columns.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
shell: don't break backwards compatibility gratuitously.

This is a partial revert of 503a2fd, where that changeset had
previously changed the names of several matchers unnecessarily.
* lib/specl/shell.lua (output_containing, output_matching)
(output_error_containing, output_error_matching): Rename these...
(contain_output, match_output, contain_error, match_error):
...back to these.
Adjust all callers.
* NEWS: Update.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>