Stan Schwertly

Not sure why or when this happened, but trying to run fuse-colors on at least 10.8.5 refuses to work. It'll state that it mounts successfully, but trying to use it...

Didn't realize I had hardcoded bash. Need to think about _the implications_

This change makes `st` a bit quicker for large inputs. The main boost comes from de-duplicating the `validate` check for every number. The validation check is also replaced with Scalar::Util's...