Weighted probability added and more

This new version (v. 1.2) has weighted probability added to the Items.json item database. Using this the drop chances from containers can be fine-tuned.

Changelog:

• Small change in "ItemIcon on drop" (event number 173) to allow easier integration with other projects. Is overlapping Frame1 now checks if Frame1 layer is visible instead of InventorySlot.

• Small change at chest loot frame creation (event number 298) to create the frame on the chest's layer instead on UI for easier integration with other projects.

• Added probability weights to the Items.json.

Hope it's useful