Remove all optimistic lock code from Lisk

Summary: We never use this and almost certainly never will. It's been in Lisk for ~7 years but is a solution in search of a problem. It causes a conflict with any DAO that has a version column.

Test Plan: Browsed around, performed inserts and updates. Edited a Phriction document.

Reviewers: vrana, btrahan

Reviewed By: btrahan

CC: aran, leslie.chong

Differential Revision: https://secure.phabricator.com/D3625