scaling on partial model fits. Also added new method
isFirstLevelAnalysis.

sorted eigenvalues. I do not understand numpy indexing.

dtifit.py. Added new function, decomposeTensorMatrix, which turns a 6
volume tensor matrix image into eigenvalue and eigenvector images.

readbuf size, despite profiling showing that it doesn't make much
difference.

as it wasn't working previously.

using a software or hardware GL renderer.

when both q/sforms are unknown. Otherwise should default to
nibabel. Also added method to MelodicClassification to return all labels.

multiple topics to be specified.

instead of props.

given topic.

passed through to listener functions.

a warning if the sub-class is also a HasProperties, because both classes
define a 'notify' method, which could be super confusing.

anymore, and might get deleted.

fixing it anyway.