[ts.manip] remove old parallel ts iterator
Bring config values from the yaml file

* timestream/manipulate/pipecomponents.py (argNames): Be more explicit about
what arguments we expect.
* timestream/manipulate/plantSegmenter.py (__init__): maxIter, epsilon and
attempts get initialized at object creation time.
(segment): Stop passing any of the arguments within the
PotSegmenter_KmeansSquare class.
(calcKmeans): Include the class attributes for the k-means calculation.
Check for segmenting method existance.

* timestream/manipulate/pipecomponents.py (__init__): Raise a ValueError if
there is no method with the name of self.method.
Use hints to default to previous mask

* timestream/manipulate/plantSegmenter.py (mask): We pass the previous iph
in the hints dictionary
(segment): We use previous mask when we think that the current mask is not
adequate.
Fix Bug. Make a copy of image when masking

We were chaning the main pot image. We now make a copy to put mask on a copy
of the main image.
* timestream/manipulate/pipecomponents.py (__call__): Use & instead of | when
masking
* timestream/manipulate/plantSegmenter.py (maskedImage): Make a copy of
self.si with self.si.copy()
(show): Use & instead of |
Make previous pots available through previous mat.

* timestream/manipulate/pipecomponents.py (PlantExtractor.__call__): Get the
previous image pot matrix from context["ipm"]. At the end make the ipm
available by replacing it in context with self.ipm.
* timestream/manipulate/plantSegmenter.py (ImagePotMatrix.__init__): Add an
argument ipmPrev that will allow for pot continuity. Use the ipmPrev to add
iphPrev to each ImagePotHandler instantiation.
* util/pipeline_demo.py (context): Stop reinitilizing the context on every
image. This allows for pipecomponents to modify the context and re-use it on
popsterior runs.
Remove ImagePotHandler from the segment call

* timestream/manipulate/plantSegmenter.py (segment): Instead of passing an
ImagePotHandler we pass an image. hints now contains the previous mask instead
of the previous ImagePotHandler.