* progmodes/octave-inf.el (inferior-octave-has-built-in-variables):
New defvar.
(inferior-octave-resync-dirs): Check to see whether Octave has
built-in variables and set inferior-octave-has-built-in-variables.
Check inferior-octave-has-built-in-variables to decide whether to
send commands that set built-in variables or call functions to
change Octave's behavior.
Send "disp (pwd ())" to Octave instead of just "pwd".
(inferior-octave-startup): Send "more off" to Octave instead of
"page_screen_output = 0".