Bump version number
Remove Apache Commons IO copyright notice
New spelling correction algorithm (#25)

I don’t know how many I’ve gone through now, 4? This change is in
response to the mentioned issue. I didn’t want to find out what was
wrong with the previous solution because it was awful and I knew that I
was going to have more trouble with it.

The new correction algorithm is homegrown and divided into two stages.
Every replacement to be made is identified, then replaced one by one.
Add message correction test case

Add new test case that tests multiple corrections at once.
Remove unused import
Make message correction case insensitive

This has always been the case, but was overlooked with the new
algorithm.
Merge branch 'hotfix-1.8.4' (Fixes #25)