Further clarification on forgetting factors

Updates after doisslintercept

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.

Add DOI SSL intercept certificate, update Dockerfile to add certificate for building within DOI network

Update IMFV122 empty values

IPython notebook updates

- 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.

Update update

Update docs

- (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

Do not try to set metadata when observatory is not known

Goes password

Changed how Popen is calling parameters,  to take care of the case of spaces in passwords and/or user names.

Reworked to pass kwargs to the base classes,  and retreived _post_process from the old IMFV283Factory.py

Timeseries factory refactor