Based on the awesome work from Joel Holdsworth making it possible to add custom widgets to the dock item grips, I finally patched anjuta to use this ability. This can save quite a bunch of pixels:

Anjuta with new buttons in grip feature

Old pixel-wasting version

There may be still some style issues especially for the message window tabs. Suggestions welcome!

I just created a tiny ppa which contains anjuta and gdl 2.26.2 as Ubuntu is a bit slow in updating those. If you are a jaunty user I really recommend an update to the latest stable version which contains some important bug-fixes:

PPA for Johannes Schmid