Testing version of getPhotonContrib() that precomputes contribs with separate radius per bin (which basically just increases noise). Also testing version of getPreCompContribByMod() that looks up multiple precomp. photons instead of just the single nearest, and averages their contribs. To support the latter, struct OOC_SearchQueueNode also includes an absolute photon index (corresponding to the file offset) which is used to cache the precomputed contribs of multiple photons. OOC_PutNearest was modified to handle the index in the search priority queue.