PATCH: BeOS Line-draw fix

[James Montgomerie]

The attached patch fixed the BeOS front-end issue of always drawing lines one 
pixel too long - you can see what I mean by looking at things like the tab 
markers in http://www.abisource.com/shots/beos1crushed_jamie.png.  I don't 
know why, but graphical glitches like this really grate with me.

It only changes BeOS files, so shouldn't affect anyone else.  If there are no 
objections, could someone commit it, please?

Jamie.

beos_linefix.zip