[boost] feature for C++ standards compliance

The serialization library is compatible with C++03 (and likely 98). And is tested regularly with C++ compilers with the -std switch set to this mode. The recent changes to the math library have broken about 5 tests in the serialization library. Since this breakage is in a few tests only and not in the library itself, I'd like to suppress these tests when the being tested with a C++03 compiler. I've suppressed tests which are conditional on C++ features which are not supported and this has worked well for my purposes. I'd like to do the same for a couple of tests which are conditional on usage of the math library and standards versions < C++11. Any B2/CMake experts want to help an old guy out?