[sugar] replace/normalize some keyboard shortcuts

[Mikus Grinbergs]

Eben wrote:
> I'm certainly all for removing alt-n and alt-p.  We don't need
> redundant shortcuts here, and alt-tab and alt-shift-tab will work fine

I disagree with alt-n and alt-p not considered useful.  Either can 
be done using TWO fingers.  Needing three fingers for backwards-tab 
navigation is quite awkward for me.

BTW, the existing XO implementation is a non-standard ctl-alt-tab, 
instead of alt-shift-tab.

[I don't actually care how you set the defaults -- I customize 
keyhandler.py on my XO for my own preferences anyway (and if that 
makes it more difficult for someone else to use my XO, I'd rather 
make things easier for me than avoid customization).]


> In general, I would say that it's silly to use basic shortcuts for
> actions that have a dedicated button on the XO (rotate, frame)

Whenever I'm at home, I plug an USB keyboard into my XO.  It is not 
silly for me to assign an unused F-key to 'frame' - again, that is 
something that makes using the XO easier for me.

mikus