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/source/FileSystem.cpp

@@ -35,6 +35,10 @@
 #   define _stat stat
 #endif
 
+#ifdef __CYGWIN__
+#define stat64 stat
+#endif
+
 namespace G3D {
 
 static FileSystem* common = NULL;