Drop broken Schema migrations

The code in the Schema_82 didn't work when upgrading from a 2.7 or an
older release to 2.10.

Drop the broken schema migrations. An upgrade from 2.7 or earlier
release to 2.10 will need to be done in two steps:

* upgrade to 2.8 or 2.9
* upgrade to 2.10

Change-Id: Ie7ae48326adb5d5c6e77190d9bf6739350a64887
32 files changed