Limit depth when fetching thumbnail folders.
Limit depth when fetching thumbnail folders.

In a directory containing 50.000 files, fetching the thumbnail folders took over 10 seconds.
Note that storing 50.000 files in one folder is very bad, but this shouldn't affect this method.
jacob-v-dam/forkcms,vytsci/forkcms,justcarakas/forkcms,sumocoders/forkcms,Katrienvh/forkcms,tommyvdv/forkcms,forkcms/forkcms,riadvice/forkcms,justcarakas/forkcms,jonasdekeukelaere/forkcms,bartdc/forkcms,carakas/forkcms,jonasdekeukelaere/forkcms,DegradationOfMankind/forkcms,jeroendesloovere/forkcms,dmoerman/forkcms,jeroendesloovere/forkcms,Thijzer/forkcms,mathiashelin/forkcms,dmoerman/forkcms,Katrienvh/forkcms,Thijzer/forkcms,jessedobbelaere/forkcms,DegradationOfMankind/forkcms,vytenizs/forkcms,sumocoders/forkcms,jonasdekeukelaere/forkcms,Katrienvh/forkcms,jeroendesloovere/forkcms,vytenizs/forkcms,riadvice/forkcms,carakas/forkcms,tommyvdv/forkcms,forkcms/forkcms,vytsci/forkcms,bartdc/forkcms,jeroendesloovere/forkcms,forkcms/forkcms,jessedobbelaere/forkcms,bartdc/forkcms,DegradationOfMankind/forkcms,jonasdekeukelaere/forkcms,jonasdekeukelaere/forkcms,jacob-v-dam/forkcms,DegradationOfMankind/forkcms,sumocoders/forkcms,mathiashelin/forkcms,jessedobbelaere/forkcms,tommyvdv/forkcms,mathiashelin/forkcms,vytsci/forkcms,vytenizs/forkcms,tommyvdv/forkcms,Katrienvh/forkcms,carakas/forkcms,riadvice/forkcms,jessedobbelaere/forkcms,Thijzer/forkcms,riadvice/forkcms,forkcms/forkcms,sumocoders/forkcms,dmoerman/forkcms,jacob-v-dam/forkcms,jacob-v-dam/forkcms,carakas/forkcms,justcarakas/forkcms,mathiashelin/forkcms,sumocoders/forkcms,carakas/forkcms