T-4 "Blue Impulse" is updated, as well as other Japanese warbirds

I've updated T-4. I guess 3D model is getting better, and its behavior using JSBSim has reached to acceptable level. With my own comparison between Blue Impulse's demo flight pattern and my T-4's behavior in FlightGear, the gaps between these are less than 10% in most case. The updated T-4 is available from Aircraft page, so give it a try. The other Japanese warbirds are also updated and available from the page. T-4 also comes with yasim model, but is not that accurate, so it's good to use JSBSim version.

Though the changes in j7w and Ki-84 are not that much, but are compatible to 1.0.0/CVS. The changes made to A6M2 is big. Now A6M2b is integrated into A6M2 and you can change its livery (texture) at any time by pressing 'l' key. You can go visit Aircraft to get these aircraft.