Video Transition / Stinger Transition 0.2.2

Sorry about the double update...
Fix for crash introduced with last version, if you would select a valid file for a transition that previously used an invalid one.

No new stuff, just fixes for the issues pointed out by Rodney.

Memory leak should be resolved (please let me know if you still encounter leaks)

The flash of the last frame of the stinger, when starting a new transition, has been removed.

The cut frame slider should now represent the exact frame during which the transition will happen. (previously it was 1 frame too early)

Also unloading some parts of the transition when it is not active anymore (meaning you switched to a different transition).

Rewrote the video render part based on the Media Source in OBS.
This fixes the issue of Inputs not being loaded with alpha values and the stinger being played too fast / slow if the framerate of the input and OBS were different.

(Thanks Gol D. Ace and Rodney for the suggestion)

If you encounter any issues let me know!