Don't depend on accuracy of pot detection

We use the minimum distance between pot centers to calculate the growM factor.
This results in bizarre errors in pot size.
* timestream/manipulate/pipecomponents.py (__call__): Use the median of the
sorted distances to the nearest neighbor to calculate growM.
Remove img from ResultingImageWriter

And make sure that all __call__ methods have a "log" line.
* timestream/manipulate/pipecomponents.py (ResultingImageWriter): Remove img.
ImagePotHandler: maskedImage -> getImage

getImage is a more general method that can return (or not) a masked pot img.
* timestream/manipulate/pipecomponents.py : call getImage instead of
maskedImage.
* timestream/manipulate/pot.py (getImage): New method, replaces maskedImage. Add
structure to add feature strings to the pot img.
Relate a range to each statistic parameter.

* timestream/manipulate/pipecomponents.py (Resultingfeaturewriter_csv.__call__,
Resultingfeaturewriter_ndarray): Make sure we call StatParamValue.value.
* timestream/manipulate/plantSegmenter.py (StatParamValue): New class that
contains logic for statistical parameter values. It adds range to the values.
* timestream/manipulate/pot.py (calcFeatures): Be sure to call value in the
StatParamValue instance.
User can now add feature values in the output images.

* timestream/manipulate/pipecomponents.py (ResultingImageWriter.argNames): We
add an additional argument addStats. Its a list where the user can define which
of the features he wants in the output image.
(ResultingImageWriter.putStatsAllPots): New Method to put all the feature text
in the image.
* timestream/manipulate/pot.py (ImagePotHandler.getImage): This is where we
actually call cv2.putText().
Add minBoundingCircle to feature calculations.

* timestream/manipulate/plantSegmenter.py (StatParamMinCircle): New class
defining the circle values.
(StatParamCalculator.mincircle): New Method that to actually calculate the min
bounding circle.
Feature printing happens in StatParamValue

* timestream/manipulate/plantSegmenter.py (StatParamValue.drawParamInImg): We
draw part of the name and the value of the parameter in the received image and
coordinate.
* timestream/manipulate/pot.py (getImage): Just call new method to draw.
Add print circle capabilities.

* timestream/manipulate/plantSegmenter.py (StatParamMinCircle.drawParamInImg):
Overload this method to print the circle instead of the value.