Prioritize single page edits over template changes

Splits single page edits onto another job type from template changes.
Because the job queue gives each job type equal attention and each job
type gets its own fifo queue the will prevent updates from templates from
getting "in front" of single page updates.  It won't actually cause single
page updates to be done before any template updates, in fact both types
will get equal weighting.  In effect, though, this will prioritize single
page updates because there is much less likely to be a huge backlog of
them.  Template updates, on the other hand, can easilly cause a large
backlog of search updates to be queued.

The goal here is to make sure single page updates get into the seaerch
index fast, like we advertise Cirrus is capable of, even if there are
tons of template changes going on.  We'll still work on template changes,
but they can wait.

This also turns on deduplication for cirrus jobs which _should_ be safe
because the deduplication only happens to unclaimed jobs.  It wouldn't be
safe to deduplicate claimed Cirrus jobs.  It should help if there is a
huge backlog of Cirrus jobs.  OTOH, we don't do anything special to make
sure that jobs are deduplicate-able.  Frankly it'd be pretty easy to make
jobs mergeable and save tons of execution time but that isn't an option
at this point.

Change-Id: I2c8ddd68dc22aca3d92ef4f7f72a68e6dbe09986
Merge "Prioritize single page edits over template changes"