Size Variations and aligning Items to Surface

[nosdregamon]

This adds two new functionalities to the scatter-Plugin:

A) Enable random size variations in size for the scattered Items. Toggle on and off, give an upper and a lower limit for the size variations.

B) Aligning scattered items with the surface they stand on. Toggle on an off. Looks fine with flat items such rocks and crates, probably quite strange for trees and pillars.

(I accidentally deleted my former pull request. Still learning how to git good. Hope I got it right this time)