Clicking bookmarklet twice will undo (not perfectly)
Complete remove role=presentation elements
Revert "Complete[ly] remove role=presentation elements"

That had some unintended side-effects.

This reverts commit 0ddc953671f35e6bb41fd97170d769f36f1e5347.
Improved toggling by caching the original HTML.
New attempt at removing role=presentation elements
Bug fixes
Also need to remove elements that have a default role presentation (div, span)
First stab at showing inputs and labels
Rounded out application of labels to form fields
Replace imgs with the alternative text.
More closely match the spec for displaying form fields.
Show labels for form fields with dashed underline.
Display announced labels when an element is focused.