Rework output/terminal_ncurses.c to be more performant
Rework output/terminal_ncurses.c to be more performant

By scanning through the updates row-by-row rather than column-by-column,
a lot of color-changing updates are saved when using a gradient. This
seems to significantly reduce tearing when running Cava through urxvt on
an X11 server.

nikp123/cava,karlstav/cava,nikp123/cava,karlstav/cava