Adding attribution to header comment
Adding binary cleanup after compilation

Function removes all previous version folders for the binary except the
most recent.
Only run cleanup when the compilation returns properly
Adding header for run section
Removing debug statement echo
Removing todo from readme

Cleanup of old binary folders is now handled automatically.

The next still will probably be to cleanup cached binaries for scripts
that no longer exist, but another strategy will need to be determined
for handling that, and it might require restructuring the caching.
Tweaking example.swift description
Editing Readme
Check for the existence of the executable and pass to swift if needed

In this version, it first checks to see if a file with the name exists.
If not, then it checks the PATH. If it's not found in either, then the
original swift is called with any passed arguments.
Tweaking headers