Beech T-34 and Fuji T-5/T-7 added

Three new aircraft types were added, but as they are very similar, this wasn't such a large effort. We are talking about the Beech T-34 (Turbo) Mentor, Fuji T-5 en Fuji T-7. The Fujis are derivatives of the T-34, hence why.

Additionally, I added a separate description for the ATR42-400, as this was clearly distinguishable from the series 300 and 500/600 after all, thanks a tip received from you visitors.