Merge branch 'ars3niy-curses256' into NetHack-5.0
Use 256 colours in curses window port
Create curses colour pairs for 256 colours
Pass base-256 colour index to curses_putch
Combine three arguments of curses_putch into one
curses: use existing background parameter for pile
replace NOTPARMDECL with TPARM_WORKAROUND
tty: handle indexed colors separately from RGB color space