Update for Windows (and various knock-on effects)

Getting things (back) up to speed on Windows has caused a few
significant changes:

* io files are now cryptio
* Ordering of header files (windows.h, winsock.h) is important! (why?)
* Using the latest Dev-C++ has changed the build settings
* At least the first two points have also caused changes for GNU/Linux
  (and maybe OS X too)