Only loop output if loop is on, fix SBS frame extraction not clearing, more

Improved Interpolate.Cleanup() with retries
minOutVidLength now defaults to 5s instead of 0s
Frames filenameMap now uses zeropadding value from Padding class

Code/Data/Padding.cs

@@ -9,6 +9,7 @@ namespace Flowframes.Data
     class Padding
     {
         public const int inputFrames = 9;
+        public const int inputFramesRenamed = 8;
         public const int interpFrames = 8;
     }
 }