General style review with Sergey
Work in progress for running Blender for real
Some small tweaks

- Made workder report progress back to the server when rendering is over
- Hooked Shot start/stop buttons to the interface
Code cleanup: make it pep8-complaint
Refactoring: job dispatching makes more sense now
Refactoring: now rendering with blender path from settings
Adding a shot now redirects to the list of shots
Running render_command now works
Small fix for jobs creation on same size chunks
Fixed small typo in job creation
Added try statement for dispatch_jobs
Added if statement for shots that are completed