I cherry-picked a few changes from master to branch-4.6.

The important fix is the index persistence manager fix that Ivan did, and
other fixes that Sam fixed.

I already update the release labels for the cherry-picked changes. However
please also take a look before you cut the 4.6.1 release.


On Sun, Jan 7, 2018 at 11:27 AM, Sijie Guo <[EMAIL PROTECTED]> wrote: