closeEnough

- Implemented closeEnough, which does a truncated, caseless compare
  between two strings.  For example, "FoO" is cloneEnough to "food."
  to be a match.  Used to allow mixed case and abbreviated arguments.

src/text.cpp

@@ -617,6 +617,18 @@ bool compare (
   return left == right;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+bool closeEnough (const std::string& reference, const std::string& attempt)
+{
+  if (compare (reference, attempt, false))
+    return true;
+
+  if (attempt.length () < reference.length ())
+    return compare (reference.substr (0, attempt.length ()), attempt, false);
+
+  return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 std::string::size_type find (
   const std::string& text,