Before adding any more features to todo_completion, I feel like I need test coverage, so this is a first stab at testing the completion results, via a new test function test_todo_completion.
Some basic tests showcase the capabilities.
Note: test-lib.sh now uses arrays, therefore all tests must use /bin/bash, not /bin/sh to avoid errors when sourcing test-lib. For consistency with todo.sh, we should have used Bash everywhere, anyway. Also note that t2000-multiline.sh needs some more quoting to avoid "Bash: ambiguous redirect" errors.
On Cygwin, clearing the executable flag may have no effect, as the Windows ACL may still grant execution rights. In this case, we skip the test instead of failing.
- Reduced duplication via common make_action() function.
- ENH: Adding proper shebang line to the custom action scripts.
- Changed output of custom action to better differentiate from todo.sh output.
