Merge lp://staging/~quickly-committers/quickly/nautilus-bar-updates into lp://staging/quickly

This is an update to the ubuntudevbar.py nautilus extension we have. It updates it to work with nautilus 3.0 (and thus uses gtk3, pygi, and the latest nautilus-python from oneiric).

The bar is still kinda crappy. It takes up lots of space, seems to slow down nautilus's first launch, and some buttons don't seem to work right (like edit) despite me making sure that we are running the command behind the scenes.

This will get the extension back to where it once was (in a runnable state), but I suspect that we should stop shipping it in the Ubuntu packaging until yet more work is done on it.

Note that this is relatively easy to test:
1) Install python-nautilus from oneiric
2) Drop ubuntudevbar.py into ~/.local/share/nautilus-python/extensions/
3) Install the quickly icon from data/icons/48x48/apps/ into /usr/share/icons/hicolor/48x48/apps and regenerate the icon cache (I generally just reinstall some app like so: "sudo apt-get install deja-dup --reinstall" because I can never remember the command)