removing small connected components

Hi guys, For my own segmentation package, I wrote a small function to remove small connected components in an ndarray. You can see it here: https://github.com/janelia-flyem/gala/blob/master/gala/morpho.py#L72 I've been looking at things that could be moved from there to skimage and I thought that was a prime candidate (I think you actually do the same thing in one of the examples, but without making it into a function). Any interest in a PR? There's other nd operations in there: morphological reconstruction, h-minima, regional (aka local) minima, and impose minima. Let me know if you would like any of these for inclusion in skimage... Thanks, Juan.