added sample stylesheet and xml that show how to transform escaped html documents that are contained in descriptions
javascript will now work with multiple .htmlContainer elements on a page
updated xml input file that uses /html/head/style to set the background color on body to green

two separate xslt files:
  1) copy the raw html to a blob and use a FileReader to construct a data uri that will be used for the source of an iframe
  2) create a temp "html" element, set it's innerHTML property to the raw html, grab it's body content and add that to the main document inline
example of setting iframe contents via iframe's .contentDocument.documentElement.innerHTML
added basic capbility for customizing header/footer/title/css
added the example customized stylesheet that was missed in the last commit.
now processTopLevelCategory includes printing the header.  the test to include/exclude the heading and table is now inside the template.

(this meant that the category label and a category identifier are now passed into the template)
now using category type specific coloring of top level tables
(this is a first cut)

note: nested content is not handled yet, just the top level tables
split the css for coloring top level category tables into a separate css file (to make these css rules easier to find and update -- a consumer might just update this css file with their own).
added threat actors, exploit targets, and incidents to color themes
removed even/odd classes on top level table since the :nth-child() pseudo class is being used (and being used on tbody groupings of rows (so the even/odd test is really easy)

removed extra tbody that was being produced on the top level category tables.  tbody elements can't nest, but you can have multiple tbody elements within a table
added two global variables to turn on/off the file metadata header and the stix header (both are turned on by default)
adding tlp, hash, icons
fixing merge
adding icons.xsl
- added svg files as separate resources (not embedded in xsl)
- now the xsl is including the xsl files at stylesheet execution time
- svg files now only have svg vector images; embedded jpg/png/pgf (pgf is adobe illustrator)
- svg files were cleaned up to remove adobe extension elements, attributes, and entity references (which were used for namespace uris)
made svg images have a height and width of 100% so that they size based on the containing html element (usually a div)

this means their size can be controlled with css properties

in the stix html output, this can be controlled with the class "itemCategoryIcon"
instead of using a table for "document contents" use a series of three nested divs

the innermost divs have class itemCategoryIcon:
  - have height and width set (just as before)
  - have display set to inline-block

the parent div is surrounding each icon block is documentContentsItem
  - it's diplay property is set to inline

there's a documentContentsItem div surround the whole list of items, but it doesn't have any styles currently applied.
added global parameter "displayConstraints" that defaults to true for allowing user to turn off the display of "cbox properties display style" constraints (e.g. properties on these elements beside xsi:type, id, idref)
replaced the repeated ids with unique ids across the svg files (since the files are included inline in the final html document).

this was a problem for firefox where all the icons were shown in the same color (safari and chrome were fine)