Define our own Node entry

Chromium's V8 is using external startup snapshot file while Node does
not, so we have to use Chromium's gin for V8 initialization.

atom/app/atom_library_main.h

@@ -13,7 +13,7 @@ __attribute__((visibility("default")))
 int AtomMain(int argc, const char* argv[]);
 
 __attribute__((visibility("default")))
-void AtomInitializeICU();
+int AtomInitializeICUandStartNode(int argc, char *argv[]);
 }
 #endif  // OS_MACOSX