cleaned up (and included) the scripts to compress/minify

* building the javascript isn't difficult.
  the command to run the RequireJS Optimizer
  was already included in the README.
  adding the shell script to the repo:
    demo/[prep]/1_scripts/run_requirejs_optimizer.sh
  just makes it more accessible to run.

* preparing the css was more difficult.
  some tooling had already been written,
  but it wasn't published.
  since the add-on needs to be updated..
  since the recent enhancements modify both javascript and css,
  including a new image that needs to be Base64 encoded..
  it seemed like a good time to clean up the scripts
  that generated the initial version of the css file.

  - the first step is manual,
    but it had already been done.
    this is to identify every image file referenced by the css.
    for each file:
      * aggregate every css rule that references a URI
        to the file into a single rule
    this file is now located at:
      demo/[prep]/2_css/manual_css_edits/all_image_urls.css

  - the remaining steps have been automated by shell scripts.
      * demo/[prep]/2_css/1_combine_css_files.sh
          - concatenates all of the css files
            that would normally be `@import` by:
              css/harViewer.css
            and writes a single output css file to:
              demo/[prep]/2_css/temp/1_combined.css

          - this script is a little more devious.
            during the concatenation,
            the css files are filtered through sed,
            and all of the image URLs:
              url(path/to/image)
            are replaced by:
              none

          - the following css file is prepended:
              demo/css/quirks.css

          - the following css file is appended:
              demo/[prep]/2_css/manual_css_edits/all_image_urls.css

      * demo/[prep]/2_css/2_encode_images.sh
          - filters the combined (but not Base64 encoded) css file:
              demo/[prep]/2_css/temp/1_combined.css
            through a PHP script:
              demo/[prep]/2_css/php/encode_images.php

          - the purpose of this script is to replace all of the
            image URLs in the css file
            (which are now limited to those that originate from
             the initial/manual step)
            with Base64 encoded data URIs.
            Doing so removes any dependency on external image files.

          - the final output is written to:
              demo/[prep]/2_css/temp/2_encoded.css

* note:
  - the scripts:
      * demo/[prep]/1_scripts/run_requirejs_optimizer.sh
      * demo/[prep]/2_css/2_encode_images.sh

    are currently configured such that the output
    (from each, respectively) is NOT minified.

    minor changes (in either) would produce
    minified/compressed output.

  - specifically:
      * demo/[prep]/1_scripts/run_requirejs_optimizer.sh
        - line 19
        - remove the command-line option:
            optimize=none

      * demo/[prep]/2_css/2_encode_images.sh
        - line 21
        - replace the value:
            minify=0
          with:
            minify=1