Fix Hue packages so that hue-shell is not architecture-dependent

Review Request #1850 - Created June 28, 2011 and updated

Aditya Acharya
The Hue packages are currently broken because hue-shell is expected to be architecture-independent, but it is not due to the existence of the setuid binary.

This commit moves the setuid binary from apps/shell/src/shell to desktop/core/src/desktop/lib.

This doesn't have to be a permanent fix - if we want we can go with an architecture-dependent hue-shell package.
Still able to create and control a subprocess from Hue.
  1. I don't think the setuid binary belongs in hue core. It's clearly something needed by only Shell (for now). If and when there's a second use case, then it makes sense to factor it out.