Compile without warnings with MSVC

This patch supresses most of the warnings that show when compiling with Visual Studio. Most of the warnings were for C4251 which is a silly warning (see http://alfps.wordpress.com/the-no_sillywarnings_please-h-file/) and for standard functions like sprintf for which Microsoft would like us to use non-standard versions.

After the preceding, Visual Studio produced only two warnings on bindings/c/tag_c.cpp which I fixed.

The code builds for me with Visual Studio 2010 and 2012 and on Linux it compiles and tests without errors with g++ 4.8.1