Issue #19464 Suppress compiler warnings during clean. Patch by Zachary Ware.
Silence a compiler warning about an unused function
Issue #19410: Put back in special-casing of '' for
importlib.machinery.FileFinder.

While originally moved to stop special-casing '' as PathFinder farther
up the typical call chain now uses the cwd in the instance of '', it
was deemed an unnecessary risk to breaking subclasses of FileFinder to
take the special-casing out.
Abstract out stat calls in importlib for easier experimentation.
asyncio: Pause accepting whenever accept() returns certain errors. Fixes asyncio issue #78.
asyncio: Fold some long lines.
asyncio: Add server_hostname as create_connection() argument, with secure default.
asyncio: Refactor ssl transport ready loop (Nikolay Kim).
asyncio: Document EventLoop.close().
asyncio: Log a warning when eof_received() returns true and using ssl.
asyncio: Various style nits.
asyncio: Better-looking errors when ssl module cannot be imported. In part by Arnaud Faure.
asyncio: Slight rearrangement of tests for server_hostname=...