MIDORI_VERSION_SUFFIX resolves to a string that needs to be
added to each extension's version at build time. If it is
different than the running Midori's, it is shown in the
extension list.
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.
