Review Request: Make area switcher usable when KDevelop runs on an appmenu-enabled system

[David Nolden]

I don't use Ubuntu, and for me this completely kills the
area-switcher. When I comment out the new code in
UiController::setupActions, it works again. Obviously
d->defaultMainWindow->menuBar()->isNativeMenuBar() returns true on my
system too, even though I have a standard in-window menu bar. The
documentation of isNativeMenuBar also states that this is just a hint
set by the programmer, and not a way to read whether native menu-bars
are used on the system. Therefore a better way to decide whether to
activate this code is required.

Greetings, David