add opener and marking functions

bind e to cmd_edit

bind v to cmd_view

bind ^M to cmd_shell

sort keybindings

implement reload

implement copy/paste path

switch to raw mode

add pledge

bind arrow up/down

add cd up/down and home

re-add jump top/bottom (g/G and </>)

fix quit type

rewrite the keybindings management use a table to define all the keys and split actions into separate functions. It's cleaner to support multiple keys bound to the same action this way (like for e.g. PAGE_DOWN and C-v.)

const-ify