0030775: Foundation Classes - Preserve application-defined top-level exception filter

0030775: Foundation Classes - Preserve application-defined top-level exception filter

OSD::SetSignal() method now accepts argument resetting handler to default.
Added new method OSD::SetThreadLocalSignal() intended to setup
thread-specific handlers (e.g. _set_se_translator() on Windows) and FPE settings.

OSD_ThreadPool now uses new method instead of OSD::SetSignal().

dsetsignal syntax has been changed so that the first argument now defines
of signals should be catched by OCCT or not;
new parameter -fpe defines if FPE signals should be catched.