Prevent bash option reversion commands in bash completion function from being appended to bash history

[rgoldberg]

Prevent bash option reversion commands in bash completion function from being appended to bash history.

Resolve #858

Checklist

• I've added at least one test that validates that my change is working, if appropriate
• I've followed the code style of the rest of the project
• I've read the Contribution Guidelines
• I've updated the documentation if necessary

[mredig]

I don't understand bash as a language enough to comment on the code, but I can confirm issue #858 is resolved in this branch!

[rgoldberg]

The cancellations don't seem to be related to the code changes in this PR.

[rgoldberg]

Is there anything that I (or anyone else) must do to get the cancelled checks to run?

The PR's change just adds in scripting to replace newlines with semicolons in the shopt commands generated for the trap, so that they all run as one command line that is not added into the bash history, instead of separate command lines that are added to the history (presumably except for the first).

The change shouldn't have prevented the PR checks from running, so I assume the problem is in the check configuration.