UI Freeze Exception Request: Open apt: URIs with Software Center

[Jeremy Bicha]

While working on getting the Gnome user docs ready for Ubuntu 11.04, I
came across this bug where apt: URIs are opened by a small apturl
installer window instead of by Software Center.
https://bugs.launchpad.net/ubuntu/+source/apturl/+bug/426215

According to the Software Center specifications, Software Center
should handle these links:
https://wiki.ubuntu.com/SoftwareCenter#apturl

Benefits of this change: When installing software from an apt link,
users will be able to see a screenshot, ratings and reviews (file
size, version number, etc.) as opposed to only seeing a small
installer window with the software description. Ubuntu Software Center
is a much better looking and more useful interface than the simple
apturl window.

Caveat: This still won't affect apt: URIs typed into Firefox as ubufox
calls apturl directly. http://pad.lv/634915  This will however benefit
apt: links in yelp.

I am already working with Jim Campbell to ensure that the Ubuntu docs
reflect this change.

Jeremy Bicha