Not sure what to think of this pull request.
There's a lot of whitespace diffs, which is fine, altough sometimes it's because I aligned comments for readability.
I however have a problem with changes like this:

   test_unit=$(command -v bash_unit)
-  if [[ -x "$test_unit" ]] ; then
+  if [[ -x $test_unit ]]; then

I always put quotes around "$variables" because it's just good practice, even if I know the only possible values are e.g. "Y" and "N". I don't agree with removing them sometimes, because then you have to scroll up to see if it's possible there would be a space in the value.
For that reason, I don't want to accept the whole pull request.