no-op: set up for slow return of traffic to ulsfo

This undoes the basic outage-move in 8e27f683, but then
re-applies it on a per-country level with notation like:

SG => eqiad, # ex-ulsfo # Singapore

From here we can move blocks of countries back to ulsfo
progressively as we gain comfort and the caches warm back
up, via sets of s/eqiad, # ex-ulsfo/ulsfo,/ .

Change-Id: Ie311d845ade7c9134ad3039e36011672adc066fd