Change statistic param calculation method name

... to statParamMethods
* timestream/manipulate/pipecomponents.py: Change to new method name
* timestream/manipulate/plantSegmenter.py: Likewise
Require skimage version greater than 0.10.1

* setup.py (install_requires): Require skimage version at install time.
* timestream/manipulate/plantSegmenter.py (compactness)
(eccentricity): Assume skimage version is greater than 0.10.1
Pots are half the dist between centers.

* timestream/manipulate/plantSegmenter.py (__init__): Change the size of pots
from 1/3 the distance between centers to 1/2.
-o OUT is optional. -f YAML is not needed.

* util/pipeline_demo.py: The output directory will default to the input
directory basename. -f YAML defined the yaml configuration filename; this is not
needed as we will hardcode an expected name into the code. If the user want to
use another name, she can define a different yaml config file path with the -y
option.