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?
Nope. Definitely does NOT work because the inequality needs to be evaluated before !*s1 terminates the loop. I thought I put a comment somewhere to that effect :P.