0.2.x protocol compatibility policy

[lann]

We noticed a minor issue in a field name. Rather than just pushing a patch release to fix it, we're going to use this as a change management exercise. I'd like to propose a policy for 0.2.x protocol changes:

• First, backward-incompatible changes are undesirable, and we should err on the side of just not making them where actual user experience is likely to be broken
• A release must be "forward-compatible" with the next release or for 1 month, whichever is longer
  • a 0.2.1 client must work correctly with a 0.2.0 server
• A release must be "backward-compatible" with the next 2 releases or for 2 months, whichever is longer
  • a 0.2.1 client must work correctly with a 0.2.3 server
• Security fixes may trump all other rules if prudent

This is just a baseline suggestion which we could update as we gain real users.