Fixes #5417. Much better performance on casts to integral types.

Adds more tests for overflow detection.
Workaround for bugs of vc8 (lexical_cast_vc8_bug_test.cpp now passes)
Fixes some inspection errors.

[SVN r72056]

test/lexical_cast_vc8_bug_test.cpp

@@ -1,3 +1,17 @@
+//  Unit test for boost::lexical_cast.
+//
+//  See http://www.boost.org for most recent version, including documentation.
+//
+//  Copyright Alexander Nasonov, 2007.
+//
+//  Distributed under the Boost
+//  Software License, Version 1.0. (See accompanying file
+//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt).
+//
+// This tests now must pass on vc8, because lexical_cast
+// implementation has changed and it does not use stringstream for casts
+// to integral types
+
 #include <boost/config.hpp>
 #include <boost/lexical_cast.hpp>
 #include <boost/cstdint.hpp>