Stubgen some more stdlib modules.

Copy doctest.pyi from 3 to 2.7.

stdlib/3/html/entities.pyi

@@ -0,0 +1,10 @@
+# Stubs for html.entities (Python 3.5)
+#
+# NOTE: This dynamically typed stub was automatically generated by stubgen.
+
+from typing import Any
+
+name2codepoint = ... # type: Any
+html5 = ... # type: Any
+codepoint2name = ... # type: Any
+entitydefs = ... # type: Any