notcurses-demo continuously polls input when redirected

[dankamongmen]

Run notcurses-demo -l7 < /dev/null, and watch your output explode with

internal_get:2563:read eof on stdin
internal_get:2563:read eof on stdin
internal_get:2563:read eof on stdin
internal_get:2563:read eof on stdin
internal_get:2563:read eof on stdin
internal_get:2563:read eof on stdin
internal_get:2563:read eof on stdin
internal_get:2563:read eof on stdin
internal_get:2563:read eof on stdin
internal_get:2563:read eof on stdin

it still runs to completion, but the input thread soaks a core as it does so.

[dankamongmen]

ok, just needed to break from the input loop following NCKEY_EOF in ultramegaok_demo(), done.