* Add API to expose if RenderQueue is available to take new jobs for a given renderer and priority
* Fix issue with calculating Blender percent complete when not starting at 1
* Rename owner / client properties to parent / children
* Add make_ready method to API
* Create and submit subjobs to other servers
* Update make_ready to update children jobs and some misc fixes
* Misc GUI cleanup
* Add background fetching to server_proxy
* Update UI to use server_proxy fetched jobs
* Fix issue getting status with empty jobs_cache
* Fix issue with jobs not appearing after switching servers
* Remove job_cache from dashboard_window and utilize server_proxy caches
* Remove jobs from table that shouldn't be there
* Streamline how we're handling offline tracking and handle connection error when fetching thumbnail
* Add ability to remove any manually added servers