wip feature: distributed point cache baking. Distributed baking works but results are sent back to master/client yet. Feature is disabled in the UI for this reason.
new feature: job and slave tags, enables filtering slaves for specific jobs
  jobs are dispatched to a slave only it has no tags or all the job's tags
  Render jobs have the tag "render" by default while baking jobs the tag "baking"
UI: Web interface additions to reflect tags and job subtypes (render/baking)
bug fix: reseting a completed job correctly resets the status to queued