working on #33

I'm trying to switch all the handling of data to a model class
I've been working on a major refactoring, which has still broken several things, but I wanted to commit anyway
Most features from the processing widget seem to work again, but I'm not entirely satisfied with the workflow at the moment
There's so much overlap between the models that I'm going to roll them all in one
Refactored the model again, now everything resides in model.py and communicates through pubsub
Slowly working my way through analysis widget
I'm not happy with how some results have to get updated, so I need to figure out how to pre-compute the results they need
Things seem to be working now, but I'm not quite happy with how it works, but at least it works again!
Added filters to only update visible results
I've been working on getting the outlier filtering working again
Moved some files to different sub-directories

I also added resize events to anything that draws in QGraphicsViews
fixes #35
For some reason the COP widget won't resize
 Also removed the padding from the measurement
Made a bunch of small changes.
fixes #39
I've given Contact its own model and am moving a lot of functionality into it
At least the application is running again, but obviously this refactoring has broken just about everything
Woops I had totally ruined update_bounding_box and I'm trying to figure out how to best organize things.
Most of the processing widget seems to work again, just need to fix storing and restoring
Fixed some small errors, like using max_z instead of length
I changed the way view gets updated, forcing a full update
fixes #36