Slightly better timeout estimation

[badb]

Right now we have fixed default timeouts values - 4 hours for task, 20 minutes for subtask. We cannot predict rendering time, but we can add a task-specific function with slightly better estimation.

For Blender:

• timeouts may depend on output resoultion, number of frames, size of reources.
• Additional estimation may be done after test.

For Luxrender:

• if halttime option is chosen, than it's simple - we should just add some time for resource transfer and providers choosing process.
• Timeouts may depend on output resolution, number of samples per pixel and size of resources.

[globatum]

@badb I noticed you opened the majority of issues on the Brass milestone page. Can you verify each one soon to make sure closed issues do not remain open? Keep rockin', bro! 👍