Core: Add support for compiling core in a cygwin-environment

- rename/readd/add G3D-patches
- give a history on the changes (some G3D-changes didn't even HAVE a patch - boo!)
DON'T MESS ABOUT WITH CHANGING DEP/* LIBRARIES AND NOT LEAVING A DIFF IN THE SOURCETRE, MKAY!?

dep/g3dlite/include/G3D/System.h

@@ -19,6 +19,7 @@
 #include "G3D/G3DGameUnits.h"
 #include "G3D/BinaryFormat.h"
 #include <string>
+#include <sys/socket.h>
 
 #ifdef G3D_OSX
 #   include <CoreServices/CoreServices.h>

dep/g3dlite/include/G3D/platform.h

@@ -56,6 +56,8 @@
     #define G3D_LINUX
 #elif defined(__linux__)
     #define G3D_LINUX
+#elif defined(__CYGWIN__)
+    #define G3D_LINUX
 #elif defined(__APPLE__)
     #define G3D_LINUX