DDA interface navigation and key input bugs [Build 1061 0.A-312-g706ccb3]

Cataclysm has been making some major leaps and bounds in terms of improvements over the last year, but some interface navigation and keybind inconsistencies still remain. I’ve tried to be as thorough as possible in documenting these but may have missed a few things. Heres a list of items which could use some looking at when development time permits:

Menus that cannot be exited with escape or spacebar:

(|) Wait menu
($) Sleep menu
(?) Help menu (Cant be exited with space bar.)
(&) Crafting menu (Cant be exited with the space bar.)

Cannot be navigated by numpad or arrow keys:

(I) Item compare menu
(?) Help menu
(?1) Key rebind menu (Cant be navigated with arrow keys.)

Cannot be navigated by numpad:

Item description side panel (i + item letter)
(i) Inventory menu
(e) Examine menu
(@) Character menu
($) Sleep menu
(*) Construction menu. (Goes blank when pressing numpad key. Pressing up/down arrow key fixes.)
(?2) Options menu
Item description side panel (i + item letter)

Other key-related issues:

Movement is still hardcoded to the arrow keys, despite being unbound in the key config screen.
Arrow keys produce “hjkl” when pressed during world and character naming, possibly other places.
Arrow keys cannot be used to “Move View” because they cause movement to happen instead.
Trying to bind an arrow key to multiple functions produces a small blank rectangle as an error message instead of saying that the key is already bound.
PGUP rebinds to (S) in the key rebind menu, and is hardcoded to climb/descend stairs in world. Also functions as back/forward navigation in some menus.
PGDN rebinds to ® in the key rebind menu, and is hardcoded to climb/descend stairs in world. Also functions as back/forward navigation in some menus.
Unbindable keys: Insert, Home, End, Delete, F1-F12, Caps-lock, Scroll-lock, Num-lock, Print Screen, Pause.
Pressing an un-assigned letter in the inventory exits inventory without a warning that "[keypress] is not assigned to any item"
Numpad does not function at all when numlock is off. Typical behavior would be to function as arrow keys, KP_Home, KP_End, KP_PGUP, KP_PGDN

Thanks for putting this together! Some corner cases like these are rather hard to notice so having a list to look at is nice.