modure: Initial module, using re1.5 (which is based on re1 codebase).

https://github.com/pfalcon/re1.5
diff --git a/py/builtin.h b/py/builtin.h
index 9c8b2b9..526157f 100644
--- a/py/builtin.h
+++ b/py/builtin.h
@@ -90,3 +90,4 @@
 extern const mp_obj_module_t mp_module_uctypes;
 extern const mp_obj_module_t mp_module_zlibd;
 extern const mp_obj_module_t mp_module_ujson;
+extern const mp_obj_module_t mp_module_ure;