Add New-style splash screens

[HHS81]

New-style splash screens for Eurocopter EC-135P2 by Thorsten Renk:
https://sourceforge.net/p/flightgear/mailman/message/35886862/

[SebDieBln]

Beautiful!
How about asking Thorsten to retake the interior screenshot using the current master? The FLI would correctly display the needles and he could show the headset holder in its vertical position 😃

[HHS81]

I think we can make some better images (though I don't have the same computer power like Thorsten) 😄

[HHS81]

I have just made some new splash screens and have added them to FGAddon and in master here. We are free to change them anytime we like. I have removed Thorstens pics, especially the one from the interior - it now shows the new correct FLI needle and the headset holder in its vertical position. 😄