How to build from source?

You need:
 python,
 python-central (>= 0.6.11),
 python-distutils-extra (>= 2.8) (not available in jaunty, don't know in other distros)
for building Quickly

To be able to use ubuntu-project template, you need:
         dpkg-dev,
         python-gtk2,
         glade,
         python-desktopcouch-records (>= 0.3), (no available in jaunty)
         python-launchpadlib,
         dput,
         bzr,
         devscripts,
         python-distutils-extra (>= 2.8) (no available in jaunty, but in pitti's ppa)

That's what prevent quickly to be shipped in jaunty, not Quickly himself. So, you should backport python-desktopcouch-records to jaunty if you wish to use the ubuntu-project template :)

What for "python-desktopcouch-records" is needed ?

python-desktopcouch-records is a binding for couchdb in python, from apt-cache show:
A Python library for the Desktop CouchDB Records API.
in short, it enables to store preferences locally or remotely :)

All of those are in ubuntu-project template, not needed for Quickly core itself.

You can get by without desktopcouch, but you'll have to remove the desktopcouch code from the generated ubuntu-project before it will run. You'll also have to set up your own database and preference handling code.