Mapped Object vid out of sync, causing all sorts of issues

Problem/Motivation

I've been running into an issue where salesforce_mapped_object.vid references a non-existent version id, ie. doesn't match any entry in salesforce_mapped_object_revision.vid

This causes all sorts of problems:
- During pull, the entity creation succeeds, but writing the mapped object fails. This leads to infinite duplicate creation.
- The mapped object fails to load, so from the UI entities appear to be unmapped.
- Others

I'm relatively sure this has to do with the revisions limit and the pruning mechanism. So maybe that needs to be looked at and revised. Maybe also an artifact of however Pantheon implements databases.

Steps to reproduce

I have not been able to reliably reproduce yet.

Proposed resolution

Ideas:

• Get rid of revisions
• Use the storage handler post-save to make sure revisions match between base and revisions table.
• Similar, but use cron to do it.
• Identify root cause and fix it.

Remaining tasks

User interface changes

API changes

Data model changes