EXT-2535 wearables saved in 2.0 don't load in 1.23

Incrementing wearable version number was a bad thing here - we want to
keep all wearables reporting as version 22 until we make a breaking change.
Reverted the version number and put in a hack to force any version 24 wearables
to be re-saved as version 22. The hack can be removed before release, as it
should only affect internal testers.

Code reviewed by Seraph

--HG--
branch : avatar-pipeline