Remove uneeded comments

* util/pipeline_demo.py: Removed uneeded comments.
Timestamp the feature array.

* timestream/manipulate/pipecomponents.py : The current timestamp is located
int time stream image object in the context dict. We use unix time for now.
Remove the ChamberHandler class

All that logic can be in the PlantExtractor pipeline component.
* timestream/manipulate/pipecomponents.py (PipeComponent.show): New method for
the parent class.
(PlantExtractor): Add all the logic that was in ChamberHandler to this
component.
* timestream/manipulate/plantSegmenter.py (ChamberHandler): Remove uneeded
class.
(segmentingMethods): New package dictionary containing relation between
segmenting method name and its respective class.
Add pot id when creating ImagePotHandler

* timestream/manipulate/plantSegmenter.py (ImagePotHandler.id): New attribute
for the ImagePotHandler class. Can be any immutable object.
(ImagePotMatrix.__init__): We use the same indexing logic that is used in the
detect pot pipeline component. We should eventually initialize ImagePotMatrix
at pot detection time.
Use the pot ids in the saved feature array.

* timestream/manipulate/pipecomponents.py: Remove FIXME comments.
* timestream/manipulate/plantSegmenter.py (getPot): Use the actual pot ids to
fetch the relevant pot.
(potIds): Gather pot ids from the pots themselves.
Remove repeated loop and raise error when outfile exists.

* timestream/manipulate/pipecomponents.py (__init__): Raise an error when
output file exists.
(__call__): Remove repeated for loop to increase readability.
Add component to output to a csv file.

* timestream/manipulate/pipecomponents.py (ResultingFeatureWriter_csv): New
component that saves features to files with the names of the features. It will
put all the files in a directory specified by the user.
(ResultingFeatureWriter_ndarray.__init__): Raise error if path exists.
* timestream/manipulate/pipeline.py (complist): Add new component to the
component list
* timestream/manipulate/plantSegmenter.py (featureMethods): Change this to a
class method. So now the call is FeatureCalculator.featureMethods.
(ImagePotHandler.calcFeatures): Change the way we call featureMethods.