Revert the majority of the memory branch in order to do a multi part migration

[bhearsum]

This is part 1 of 3 to give us a smooth upgrade path for #346. This part backs out most of the original patch. The parts that remain are the addition of the memory and instructionSet columns (we're doing a plain add there, instead of a renaming of systemCapabilities), and the changes to the rules tests -- because the new columns show up in the responses. With this patch, the old and new columns will all be in the db, but only systemCapabilities will be used when fulfilling update requests.

I verified this series of patches by starting off on 741a56c locally, and then applying each patch in the series - verifying that the correct updates were served for each, that the admin interface worked, and that tests passed. I intend to have stage's database downgraded before merging this (much easier to do that than to try to cope with the migrations from #346 being in one database but not the other IMO).

[nthomas-mozilla]

Looks good to me. I reviewed based on the net effect of the initial landing and this backout (specifically f8d9bd8...mozbhearsum:2e4ebda457b98aeb7aff406a1ea3aed3a5e6598a).