fixed iamplacingblocks

[Diver Down]
Added thumbnails but still fucked the mats and texts, next update fixed everything and fixed the folder layouts.

[Diver Down]
First uploaded the addon.
Map "iamplacingblocks" was broken due to materials and textures not properly sorted / packed into the bsps.
Map thumbnails were left out too due to my mistake of deleting everything but maps folder. Stupid me. Wow