bitbake: lib: fix most undefined code picked up by pylint

Correctly import, and inherit functions, and variables.
Also fix some typos and remove some Python 2 code that isn't recognised.

(Bitbake rev: b0c807be5c2170c9481c1a04d4c11972135d7dc5)

Signed-off-by: Frazer Clews <frazerleslieclews@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/server/process.py

@@ -25,6 +25,7 @@ import subprocess
 import errno
 import re
 import datetime
+import pickle
 import bb.server.xmlrpcserver
 from bb import daemonize
 from multiprocessing import queues