[Gtkradiant] bug-fix for gensurf's bitmap loader

[Martin Gerhardy]

>  Importing bitmaps by the gtkgensurf plugin was giving me a seg-fault.
> The bug was a simple size mismatch when reading the bitmap's header, a
> tough bug to find though. I changed a few other items in the file but
> nothing affecting the operation of the plugin, mostly just style.

Hi,

i've commited your patch to trunk now - thanks.

Martin