neuron_veiwer: Added support for arrays have no time dimension (just an image).
NeuronViewer: Added lines to view regression images (commented). Added support for viewing the maximum projection of the dictionary and image.
batch_learner: Broke up some lines into smaller lines. Cleaned up some comments and docstrings.
pathHelpers: Copied from ilastik code base. (Do not want to depend on ilastik while developing code for the Svoboda lab plugin. This will change in the future.)