jhatwich/layer comps+size

To use this feature add a layer comp and name it something like "overview.png" or "200% overview.png"
We are doing more testing and it looks like the high-end of the index is reliable to just sample that way, the low end of the range might be nested.  Luckily it looks like PS doesn't care if you guess low, so 0 seems to work as a suitable low.  I plan to go back to just using the range until we find a test case that fails (and still fails after a cup or two of coffee).  Sorry for the confusion.