Architectural fix allowing the "tip" popups (FOV, view name, etc...)

Architectural fix allowing the "tip" popups (FOV, view name, etc...)
to pop themselves down while the simulator is paused.

The problem was with the "real time" queue in the event manager,
causing the third argument of Nasal's settimer() (a flag for "sim
time") to be ignored.  Inverts the default sense of the argument, as
there are lots of uses of settimer() in the current code, almost none
of which want to use real time.

Note this fix introduces a header file incompatibility in SimGear --
be sure to update.