Imported Visual Studio solution into Visual Studio 2012.

 Copied config.hpp into src/main/c++/.

I have adjusted the *.vcxproj files to use the right paths in the src subdirectory. I also add config.hpp into the c++ source directory so that jzmq.hpp can be build.

I have left my Include Directories settings and Library Directories settings. Zeromq is installed into C:\ZeroMQ, the jdk I used is in "C:\Program Files (x86)\Java\jdk1.6.0".