Release version 2.0
This is a major update, almost a complete rewrite. A lot has changed,
including the name, interface and core functionaltiy. The intent remains
more or less the same.
Why the change: see c941877.
What changed:
* Stop tweaking the text layer; act directly on the canvas
* Properly apply a color scheme: preserve monotones and accents
* Accurate color transformations based on color science
* Process/leave images instead of show/hiding them
* Move the UI to its own separate (accessible) toolbar
* Remove the PDF.js wrapper; this is now addon-only
So we lose on changing fonts, but gain big on changing colors. (In fact
I had come across some PDFs with really good fonts and that partially
prompted this rewrite.) The wrapper should have been in its own repo
from the beginning.
Way forward:
The project has now taken a concrete shape; more drastic changes
are not likely. Next step would be to implement some left-out features,
like handling gradients and patterns.
