variable directly in tgetent by stderr or stdout output speed.
It helps hide in non-standard __set_ospeed function and remove it
from other sources (coming soon).
Do prototype cleanup too.
Basically all termios+termcap pgms needs it.
It set ospeed variable using nearest-matched stty speeds,
which helps termcap pgms works with non-fixed termios speeds
and not duplicate ospeed switch into every pgm.
Also it isn't standard function, its source code is too big to include it
in whole to every termcap+termios pgm.