As of now, there is no such functionality. It may be added if you file a feature request. You can make a feature suggest by submitting it as a "bug" at bugs.launchpad.net/ubuntu .

Mark the bug with the tag [Wishlist] and the developers will know there is a demand. Only the maintainer of a project or bug superviser can then change the "Importance" to "Wishlist".

The link to actually file a bug "Report a bug" in the top right corner leads to a page, where the possibility to file a bug is hard to find. The link can be found in the section:

Tips and tricks: Filing bugs at Launchpad.net

It is also possible to file a bug now at the console if you type

ubuntu-bug

into the console and follow the instructions.