R1:635bd1ef07c2

Hovercard front-end code & stuff

Summary:
Refs T1048; Depends on D5557, D5558

They hover right above your eyes. Try it out at home :D (in that case, don't forget to checkout D5557 and D5558)

Worth a lot of improvement. But it's great for now after a little bit of styling.

Scrape load (search current document for all hovercards and pre-load them) and lazy load (e.g. previewing comments which is not covered by scrape load) implemented.

Added some seemingly useful graceful situations. Too much to the…