Duff Stewart had several helpful comments regarding the last commit for this PR.
These were addressed, along with some additional minor Notebook clean-up.

- fixed datetime labels on plots so they are readable
- added another example of a constrained estimate that might be useful

Fixed a number of issues with the Adjusted Data affine transformation matrix generator
in the IPython Notebook AdjustedPhase1GenerationTool.ipynb:

- original version mistakenly pointed to geohazards server for baseline web service,
  which requires a password; we only needed to read baselines, not write, and this
  functionality is provided by the geomag server.
- original version choked if only 1 baseline set was available when extracting a
  pier correction from the set
- original version did not filter time stamps quite right; updated version at least
  does not include times not requested, although it may return fewer than expected if
  the timestamp associated with a baseline set is later/earlier than the measurement
  times (this frequently happens due to a bug in the webabsolutes package that has
  been reported)
- generate plots with datetimes
- added non-active cell that constrains the affine transformation matrix to apply a
  uniform scaling factor instead of allowing separate scaling for different vecor
  components
- redid the pseudo definitive data calculations based on average baselines to better
  reflect how MagProc software works.
- inserted/modified markdown and docstrings to better describe what is going on.

In response to Abe Claycomb's technical algorithm review, I attempted to
further clarify how alpha, beta, and gamma work. This includes a link to
a third-party website that does a good job of explaining what the "average
age" of an exponentially smoothed series is. SqDist.md will need to be
modified at least once more when the OFR is complete, so that it can
link to the official USGS documentation in addition to all the supporting
documents and websites.

- improved explanation of exponential smoothing, and how the alpha,
  beta, and gamma parameters work in SqDist.md.
- cleaned up command-line examples in SqDist_usage.md, and incorporated
  a description of the programming interface that was previously in the
  IPython/Jupyter notebook.
- removed programming interface description, and cleaned up markdown
  accordingly; re-ran entire notebook and regenerated graphics.

- (hopefully) a more clear explanation of how --sqdistd-alpha, --sqdist-beta,
  --sqdist-m, and --sqdist-gamma options work;
- actually tested the examples against an updated geomag-algorithms install,
  and it works!

- changed default values for alpha and gamma for command line script
  to zero, which means SV and/or SQ do not evolve over time
- modified SqDist_usage.md to show how to explicitly set alpha and
  gamma to desired values
- MUST modify production scripts to explicitly set alpha and gamma
  before accpeting this pull request.

Made a minor change so that the link in the SqDist.md now points to
SqDistValidate.ipynb instead of SqDist.ipynb. Other very minor edits.

- updated Ipython notebook to used SqDistAlgorithm class and methods
- added unit tests
- added functional tests/demonstrations
- added lots of explanatory Markdown