I've committed a change to the scrolling behavior. Here is how each way should scroll:
- Page down, down, space: Scroll to next page.
- Page up, up, backspace: Scroll to previous page.
- Home: Go to start of section (this may or may not be the start of the document).
- End: Go to end of section (this may or may not be the end of the document).
- Mouse wheel: Scroll by 20% of page either up or down (this may not be 20% depending on the sensitivity of your mouse wheel).
- J: Scroll 15 pixels down.
- K: Scroll 15 pixels up.
- H: Scroll 15 pixels left.
- L: Scroll 15 pixels right.