Reconfigure and finalize version-handler features

[briandominick]

Big big commit here. There are actually still some docs missing, but I want to show this to a few people and maybe even get a review before merging. This does a lot, and any messes it makes can still be dealt with, but I really want to get this out as the main feature set for 0.2.0.

This commit refactors most of the non-vendor JavaScript, including a full rewrite of the toggle handler and completion of tabber, swap, and amend version handlers.

• breaks theme JS file up into tail, tabber, toggler, semantics
• adds 3 new liquid includes:
  • versioning-controls.html translates AsciiDocsy config objects
  • version-handler.html forms the HTML and JS for most handlers
  • string-eval.liquid converts an onject's string form to data_obj
• adds full docs, including an overview & numerous examples
  • adds example files and a reference table snippet
  • adds config page for each handler type (verb)
• adds liquify filter to enable Liquid templating in our YAML source
• other accommodations such as layout, CSS changes

[JayGupta6866]

How may I assist here ?