Rename binding to metaids

Metaids in the pots reflects more the purpose of these variables and methods.
* timestream/manipulate/pot.py (getMetaKeys, getSbindList): Replaced old method
with Metaids method.
(getMeta, getSbind): Likewise.
(setMeta, setSbind): Likewise.
Create new component PopulatePotMetaIds

* timestream/manipulate/pipecomponents.py (PopulatePotMetaIds): new component
that will create additional meta ids for each pot in ImagePotMatrirx instance.
Though we have populated the meta ids, we have not way of accessing because we
can't (yet) make the ImagePotMatrix instance persistant. We don't make it
persistante because the ImagePotMatrix instance cannot be handled by json.
* timestream/manipulate/pipeline.py (complist): Fix small bug.
Start passing TimeStreamImage

* timestream/manipulate/pipecomponents.py: For all the components that passed an
nd.array as the image, we have changed it to a TimeStreamImage object.
* util/pipeline_demo.py : We now start of the process with a
TimeStreamImage instead of an nd.array.
Allow user to change configuration parameters.

We are not able to change parameters that are more complex: like a list of
values.
* util/pipeline_demo.py: Add a --set options that will parse comma (,) separated
option specifications.
* timestream/manipulate/configuration.py : Fix error where we were evaluating a
non-existing element.