BUG 1070001: Re-Org Stylus - wiki

- Separated classes and IDs in wiki.styl into individual files. 
- Moved some declarations into wiki-edit or zones to be dealt with later. 
- Added comments where I had to look up the purpose of declarations.
- Reduced specificity where I could do so quickly and verify I hadn't caused problems.
- Introduced new comment syntax (long lines) meant to indicate comment hierarchy.

As a side effect I made improvements to:
- . topicpage-table
- standardized on "revision" prefix for components on history page, removed appearances of "choice-" prefix
- standardized on "move-lookup-" prefix for components on move page to do with parent look up, removed appearances of "parent-suggest-" prefix
- made .documents into a utility class .document-list

Suggested pages for testing:
- https://developer-local.allizom.org/en-US/docs/
- https://developer-local.allizom.org/en-US/docs/MDN/ContributeMozilla/Debugging (changes could affect every part of page, document head, left, right and center columns, footer)
- https://developer-local.allizom.org/en-US/docs/Mozilla/Debugging$edit (expand the page-properties & look at editor)
- https://developer-local.allizom.org/en-US/docs/Mozilla/Debugging$history 
- https://developer-local.allizom.org/en-US/docs/Web/HTML/Element$move (look at list of sub pages, use "Lookup by Document Title" tool)
- https://developer-local.allizom.org/en-US/docs/Debugging_JavaScript$delete
- a page with a kumascript error

Another small nitpick. Should we use spaces instead of tabs?

I'm sorry all of my comments are about nitpicks. I think it says something about the great quality of the changes in the larger sense. :-)