Iterating an array by a GList is considerably faster than
continuously retrieving items, however it is also a lot
more complicated. So the new macro takes care of that and
uses a new semi-private function to avoid copying the list.
Note that the macro can't be nested, which basically isn't
useful in practise anyway.
Extensions can be unavailable on a particular platform or a system
lacking a build-time requirement. Let's handle this more cleanly
and reflect it in the Extensions panel.
Extensions used to look for the menu and append items manually.
In order to show Tools in the Compact menu a proper signal
is needed.
Adblock, Shortcuts and Toolbar Editor are ported to the new API.
