Merge the latest unordered changes. These are concerned with getting the tests

working on more compilers. The biggest change is that the exception tests have
been changed to use a very simple exception testing mechanism on top of
lightweight_test. This was because Boost.Test exception testing isn't working
on several platforms. I'm trying to set this up so that I can use Boost.Test on
compilers which it completely supports, and lightweight test on others.
Boost.Test tests more than my simple exception testing code ever will so it's
worth using where I can.


[SVN r42698]

test/exception/assign_exception_tests.cpp

@@ -4,10 +4,6 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 
 #include "./containers.hpp"
-
-#define BOOST_TEST_MAIN
-#include <boost/test/unit_test.hpp>
-#include <boost/test/exception_safety.hpp>
 #include "../helpers/random_values.hpp"
 #include "../helpers/invariants.hpp"