[boost] more fixes in como-vc71

I have received two more fixes from Comeau for libcomo 31, run on como 4.3.3, backend MSVC71: - better support for "long long" type - "int swprintf(wchar_t*, size_t, const wchar_t*, ...)" is available As usually, all fixes are available to everyone upon request. I believe these fixes will be incorporated into future version of libcomo, but this might require some more work (eg. make swprintf available on other backends etc.). B.