Repeated OGC WMS harvest leaves behind orphaned resources - ID directory/thumbnails

[awalsh]

Using 2.4.3 GN and also the BlueNet GN repeated (periodic) harvest creates a new set of ID numbers directories and resources (thumbnails) in the data directory but doesn't remove the old set of ID numbers directories and thumbnails. E.g harvest 1 gets 4 layers and makes ID directories/thumbnails 10,11,12,13 then harvest 2 runs and makes ID directories 14,15,16,17.

The end result is an ever increasing number of orphaned directories/files especially if harvests run frequently.

Suggest a way to fix this is to remove the old directories/thumbnails or more efficient re-use the same IDS on each re-harvest.

[Fxp]

r6312