When browsing around the strutil files I found a function
that was never referenced inside the code base
"void StripString(string* s, const char* remove,
-                                 char replacewith);"

The name was kind of misleading as well and it seems like
it's a carbon copy of
"void ReplaceCharacters(string* s, const char* remove,
                                       char replacewith);"
(even the parameter names are the same, the code is the same..)

Is it intentional? Maybe for compatibility reasons? If so,
let's make it deprecated and use the ReplaceCharacters method inside
or the other way around.

Also, noticed there were no tests for "StripString" or "Replace".
Added some for both and planning on maybe making it more C++ish (?)
in another commit.