Fix outputs in rezToPhy.m

[efjepsen]

The second output argument, clusterIDs, is now appropriately assigned, and calls to rezToPhy that assign outputs to workspace variables no longer produce errors.

Previously, the following error would be produced:

>> [spikeTimes, clusterIDs, amplitudes, templates, templateFeatures, ...
templateFeatureInds, pcFeatures, pcFeatureInds] = rezToPhy(rez, savePath);

Output argument "clusterIDs" (and maybe others) not assigned during
call to "rezToPhy".