Improved Executable Argument Parsing

[ObliviousHarmony]

All Submissions:

• Have you checked for duplicate PRs?
• Have you added an entry to the CHANGELOG.md file's [Unreleased] section?

Changes proposed in this Pull Request:

This pull request adds the split-string package to replace the regex parsing of executable paths. This will provide more comprehensive quoting behavior across operating systems and better cover Windows paths.

Closes #97.

How to test the changes in this Pull Request:

1. Add arguments to an executable option.
2. Confirm that they work correctly.

[ObliviousHarmony]

After further debugging, it actually looks like this backward-incompatible change is the main culprit. I'm still going to keep the nice argument parser because it's a more comprehensive solution, however, I've followed the advice of the CVE for a fix.