SimpleString::StrCmp (2)

1. This implementation works
2. StrCmp and StrNCmp should be similarly implemented (whichever way)
3. More complete tests for both
4. @basvodde Not quite what you had in mind?
Yes you can use a for loop here. I think you could delete 71-73. I guess it's a matter of preference; I slightly prefer while constructs, but yes we can do that. Only I would then want to make StrNCmp() match as well.