missing function: surfing_inds2subs, plus a possible minor path issue in defineSearchlight_volume.m

Hi all

It seems like the function surfing_inds2subs.m is currently missing from the toolbox (I suppose it is being fixed?). I noticed this when trying to run defineSearchlight_volume.m that calls this function.

In addition, line 51 in defineSearchlight_volume.m tries to add the "surfing" folder to the path while actually the folder is called "surf".

Best
Andres