We already have a magical gtk+ toolbar code, but it has been found too ugly (if there are many actions possible, that makes a too crowded interface).

The idea is the following : have a toolbar prepopulated with a few icon buttons, but all disabled, which would implement the Ekiga::MenuBuilder interface. When said toolbar gets through an object and receives a list of actions, it does the following :
- generally, nothing (!) ;
- when the name of the new action corresponds to one of the icons, then enable the corresponding button, and associate the callback to the click action.

This makes it possible to have a toolbar with a very limited number of buttons (say, two: "Call" and "Message"), which are only active when needed.

Notice that if two actions of the same name are activated, the simple button doesn't allow a choice (probably the first such action should be default, then).

Notice that since the roster view widget emits a presentity-selected signal, and the call history should become a widget with a similar signal, then the main window could have a nice magical toolbar.