Fixes#4288.
- Default imports to THIRD_PARTY, so in effect we merge the FIRST_PARTY and THIRD_PARTY stubs. This means import order is no longer affected by whether typing_extensions is installed locally.
- Treat typing_extensions, _typeshed and some others as standard library modules.
Note that isort master is very different from the latest release; we'll have to do something
different if and when the next isort release comes out.
* Add xmlrpc client module
* Add xmlrpc server module, update client
* Fix mypy errors with protocol and Dict fix
* Add Type[] around requestHandler
* Fix docroutine incompatible override
* Whoops, ignored is also missing
* Remove unnecessary str/repr overrides
* Remove unnecessary __eq__ and quotes around Unmarshall. DateTime __eq__ left for now
* Fix problems from review
* Fix various version-specific differences, make request_type conservative (only bytes, guaranteed to have same len as number of bytes)
* Silly misspelling
* Change from IO to ad-hoc minimal protocols
