combinesplit.py does not handle tracks which are split into two segments

[JarredAllen]

The combinesplit.py file does not correctly handle ants who are in an ROI while the split portion of the pipeline separates the input video into two smaller videos.

I am not going to fix this because our videos for this summer are 10 minutes long, which is what we split the videos into, so this summer's videos are not split into shorter segments, but future pipeline developers may wish to keep this in mind.