Get the tests warning free with gcc, and add conceptual-header-inclusion tests.

[SVN r57948]

test/static_log2_include_test.cpp

@@ -0,0 +1,14 @@
+//  Copyright John Maddock 2009.  
+//  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)
+
+#include <boost/integer/static_log2.hpp> // must be the only #include!
+
+int main()
+{
+   boost::static_log2_argument_type arg = 0;
+   (void)arg;
+   boost::static_log2_result_type result = boost::static_log2<30>::value;
+   (void)result;
+}