[boost] [test] new feature - colored output

Hi, I've implemented a change in regular human readable log and report outputs. You now have an ability to tell the unit test framework to produce colored output. New boolean runtime parameter is added: Environment variable: BOOST_TEST_COLOR_OUTPUT Command-line long: --color_output Command-line short: -x. By default the feature is disabled. Any comments are appreciated. Specifically: how does this feature works in different environments and if there is a way to make MS compiler to work properly (gcc on windows works fine in Windows shell, while msvc build does not) Gennadiy