Replace existing images in library and for tools

Images are available as PNGs in sizes 40x40 and 76x76 px on Google Drive:
https://drive.google.com/open?id=1qypyTUapqMJJc2IMsXgcOw5n5XJEH-gt 

The file names  may not be clear in all cases, but this document lists the essentials components/tools as they are known in Essentials and depict the new image in the column on the far right: https://docs.google.com/document/d/1UQVaknULGmZAEYJ4vy3D1OvtbghXao7i0_wMIO1g2dQ/edit?usp=sharing