Starts connecting ref question marks to docs

- Giving data "target" to the ref buttons as well, planning
to follow same procedure.
Almost there with the ref to doc connection

- Clicking on the reference item question mark triggers a click
on the matching menu item.
- NEEDS FIXING: When there's no "back" pressed between reference
question marks clicked, they just pile on top of each other. Two
ways I can think to combat this:
 1. Add yet another div with an id so that the contents of that
 div can only be one thing
 2. Simply remove ".current" from everything before making this
 think current (as is now done when the back button is clicked,
 but this time do it when the thing is revealed).
Fixes overlay of text on ref "?" click and text of back button
Merge pull request #21 from knod/reftodocs

Reftodocs - reference question marks will trigger the relevant documentation to appear