#259 Prestel has 25 rather than 24 lines

[Nigel Reed]

The Prestel terminal should only have 24 lines not 25. 1 line for the header, 22 for text/data and the last for input/status messages.

When using something like goto 0,0 then cursor up it should put me on the 24th line but it's on teh25th, which will possibly skew pages or accidentally make them larger than they should.

[Nigel Reed]

You can close this one per discussion on irc. thx

[Stephen James Hurd]

Status line.