FIXED New Custom Tree Tiles added to Lumberjacking

[Archaaz]

Thanks to @Voxpire for helping me fix a long standing issue with Lumberjacking, whereby custom tree art tiles, such as the snowy trees in and around Minoc, were not being recognized, and thus were not harvestable. I also fixed an issue whereby generic tree tiles, such as the trees in the jungle, were not harvestable.