Bind UP to action_up
Implement C-u and C-d
Implement action_top
(mostly) fix scrolling up from EOF
most: implement scrolling up

This only works on seekable files. TODO: Implement read caching overlay
stream which makes non-seekable streams seekable by stashing reads in
Add more scroll down bindings
Implement scrolling down
refactor line drawing and add configuration
reorder state struct
Draw ellipsis at end of long lines
Initial commit