[ptx] GUI layout change + Multithreaded remapping added to CVS

[Pablo d'Angelo]

Hi,

I have reorganized the GUI a little bit, the lens tab was becoming too
crowded with the vignetting correction.

Also, support for multithreaded remapping has been added to hugin and nona.

The number of threads that should be used during remapping
can now be selected in the preferences panel, or with -t arguments of nona
and nona_gui.

Does anyone know how to determine the number of CPUs and cores per CPU on
windows, linux and mac?

ciao
   Pablo