PDG stuff

[johnnyquest]

• would be nice to have progress bars on work items (ALF_PROGRESS)
• dedicated log viewer with refresh button
• cook times in some human-readable time as opposed to seconds
• store/display timestamp of the start of the last cook (==how long the workitem's been running)
• have an "attrib diff" on work item info, just like with regular attributes in SOPs
• ctrl+F find in MMB info window
• modifying downstream (or even independent) graph stops processing of graph? booo productivity killer
• (???) a bit more granularity for workitem states (e.g. "scheduled" instead of "running" if it's picked up already but waiting for a machine) (maybe this is a weta-only thing?)
• optional view: color coding work items by attributes hash (work items w/ same attribs have same colors)