Provide a GUI option in the installer to enable popcon

[Andrew Sayers]

This argument must have been had before, but recent events have prompted 
me to suggest it anyway:

	The "submit statistical information" page in "System >
	Administration > Software Sources > Statistics" should be
	presented during the installation process.  The box should
	be checked by default in pre-RC versions of Ubuntu, and
	unchecked in stable versions.

This would enable or disable the Ubuntu Popularity Contest 
(popcon.ubuntu.com), which is currently installed but disabled by default.

This would allow us to make decisions based on far better information, 
such as:

* Calculating a precise trade-off between "number of users" and "number
   of bytes", to help decide which programs go on the CD
* Checking whether applications aren't getting bug reports because they
   don't have bugs or because people aren't using them
* Spotting sudden spikes or drops in program usage that suggest a bug
   has been introduced (or give hints as to the seriousness of a bug)
* Testing whether ordinary users are going out of their way (not) to use
   a particular program

It's not currently possible to make strong claims based on popcon data, 
because only a small number of people bother to hunt it out and check 
the box.  This is a self-reinforcing problem: why should I bother if the 
data is worthless anyway?

It strikes me as reasonable to enable this by default in pre-RC versions 
(why are you running alpha/beta software if not to give feedback?), and 
reasonable to at least ask in final versions (even the laziest user is 
enabled to make his or her individual contribution).

If just 1% of Ubuntu users tick the box, that gives us enough data to 
improve Ubuntu by justifying our decisions with evidence.

	- Andrew