[engine] More pickle cleanups
Review Request #3577 - Created March 17, 2016 and submitted
|kwlzn, patricklaw, stuhood|
Some small stuff that was left out by previous reviews.
Looks like all the weirdnesses we had with pickle can be explained by the default memo mode.
Now with https://rbcommons.com/s/twitter/r/3574/ turning off memoization, I am able
to clean up two more TODOs related to pickle:
- Use binary protocol by default, was forced to use text protocol.
__setstate__, now with binary protocol isn't necessary.