Changed body font
Version bump from 2.1 to 2.2

Changed min version back to 36 because of new es6 map/set shim (after
testing on chromebook with os 36 where it works when experimental js
features are disabled)
Made progress on some urls
Minor change to comment
Treat leading/trailing HR elements as trimmable
Improvements to template based removal

Also cleaned up some comments, moved template-based blacklist filtering
to preprocess instead of postprocess, simplified exposing of attributes
and deprecated the EXPOSE_ATTRIBUTES option flag, added several
blacklist selectors