Now, rather than the bit-too-alarming stop sign, threaded wmJobs
display a progress indicator in the header. This is an optional feature
for each job type and still uses the same hardcoded ui template
(could use further work here...).
Currently implemented for:
Render - parts completed, then nodes comped
Compositor - nodes comped
Fluid Sim - frames simulated
Texture Bake - faces baked
Example: http://mke3.net/blender/devel/2.5/progress.mov
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