Removed model_id from Model objects, which in any case in managed by session.  But tests aren't passing; need to investigate further.

Moved project file into model.params; removed autogeneration of segmentation model from pixel predictions model

Disabled generation of ilastik object model that receives segmentation masks from one that receives pixel probabilities; this was causing inaccurate results

This reverts merge request !16

Generate an InstanceSegmentationModel from an IlastikObjectClassifierFromPixelPredictionsModel given binarization parameters

Removed PatchStackObjectClassifier, merged this behavior into IlastikObjectClassifierFromSegmentationModel

Raise error if ilastik data not embedded in project file; but it appears that most test classifiers fail this