job and frame status cleanup (move to the model module)
record transitions between states in job to be able to get (among others) the started and finished time.

invalid operator return value when downloading results from a job with no finished frames

Support for secure connections between Master/client/slave using SSL/HTTPS

Fixed a bug with total job time on web interface (wrong value)

- distributed point cache baking
- (baking fluids or anything else needs to be added but is not a hard task)
- master support getting all results as a zip (rendering, baking or otherwise), available as a link on the job's page in the web interface
- framework to support multiple result files per frame/task (needed for baking)

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

correcting smoke domain modifier type restriction

Patch by Philippe Van Hecke

Fix for #26867

Hunted down and debugged with great help from Geoff Murphy

Reported by Tobias Kummer. Thanks! :) 

- remove/comment unused variables
- remove unused imports
- fixed some bugs using incorrect variables

Report by Wintch Analyzer

Refill the rna blacklist list every refresh (safer that way).