Avoiding collision between winsock2.h and windows.h

[atrantan]

Collisions occur when we integrate hpx in other project that uses windows.h. This is due to the file hpx_fwd.hpp that includes winsock2.h. To avoid this, the most convenient solution is to create an intermediate header file as described in the link below:
http://www.zachburlingame.com/2011/05/resolving-redefinition-errors-betwen-ws2def-h-and-winsock-h/

[hkaiser]

Not sure what we can do about this. Creating an intermediate header file makes only sense if the user includes that file before she include windows.h. That's outside of our control. At the point when hpx_fwd.hpp is included it's already too late to do anything about the problem.

[hkaiser]

This can be closed (the issue will be solved in NT2)