We want to have two build targets: Main and MainNoGUI, and this code
will be linked against in both cases, so the ifdef isn't enough for
this case.
Just append to a vector of strings, and then convert it after the fact.
This was used to send fake button or key events to every backend to
implement freelook. When I ported these to be based on wx events in
commit 5248211, I didn't realize that these were now unused, so I didn't
remove them. Do that now.
