fix in structure alignment of btMultiBodyLinkDoubleData and btMultiBodyDoubleData

causing serialization issue in  URDF/SDF loading in double-precision mode on Windows 32bit.
(it was fine on Mac/Linux 64bit)
bump serialization version to 2.85, as we change the file format
fix in name clash in makesdna.cpp -> intptr_t is already defined.

Extras/Serialize/HeaderGenerator/apiGen.cpp

@@ -220,7 +220,7 @@ int main(int argc,char** argv)
 	fprintf(dump, "%s\n", data);
 
 	
-	char* filename = "../../../../data/slope.bullet";
+	char* filename = "../../../../data/r2d2_multibody.bullet";
 	
 	if (argc==2)
 		filename = argv[1];