Modifies the code that manages the "summary width" so that it is controllable
on a slice-by-slice basis; it's triggered out of the `parse_and_validate_options`
method, so it's actually even more granular than that. In this commit, we have
added a new argument to that method (with a default of `nil`, which will result
in the default value of 32 characters being used for the summary width) that
can be used to adjust this on a case-by-case basis (to avoid wrapping of
summary information for the help output of some of the slice commands)