Changed checks for _MSC_VER from > 1700 to > 1800

Many c++11 features, such as noexcept are not yet implemented in MSVC
2013, and we should check appropriately. these changes should fix that.

I can build the lib, but no the test exe from the VS2013 command line
I can build the lib and the test exe from the VS2012 IDE w/ Nov 2012 CTP
compiler

There are some linking issues, and perhaps some build/target issues using
bjam with msvc