Add: Selection sort algorithm to feature menu.

Implement:
        Use typedef, avoid type wrong long expression.
        The String to_lower_case isn't in the standard library, So I
          demonstrate a most cleanest/straight way to implement it.
Ref: exploit ASCII rewrote to_lower_case func.

Talk is cheap, show me the code.
Add: improve selection sort algorithm.

Implement:
        This version of selection isn't the fastest possible, but it's
          one of the simplest.
        Macro defined global function, and limits the scope of that
          function to the rest of the source file being complied.
Add: remove M$ pre-compiler secure warnings.