Function: to_title

--Usage--
> to_title(some_string)

Convert a string to title case, where each words starts with an upper case leter.

--Parameters--
| @input@	[[type:string]]		String to convert.

--Examples--
> to_title("ABC")     == "Abc"
> to_title("123 aBc") == "123 Abc"

--See also--
| [[fun:to_lower]]		Convert a string to lower case, @"aBc" -> "abc"@.
| [[fun:to_upper]]		Convert a string to upper case, @"aBc" -> "ABC"@.
