Toolbelt & other quality of life improvements — Atomcraft Steam update #638420

This update adds a Toolbelt Upgrade that lets you change between different rows of the Toolbar! I am working on a similar upgrade for the Materials bar as well; that will be in an upcoming update. :)I also added a bunch of quality-of-life things people have suggested:Middle-mouse-button functionality is improved: if the hovered pixel is a static buildable it will select the material that builds into it; it will also fallback from that to any specific drill target the material has. The middle mouse button also visually sends the swatch to the inventory slot.Brush-sizes for the Hand, Blender, and Laser (width) are now saved/restored in the player savedata for convenience'M' hotkey has been added to jump to the Map tabMap generation has been made much more efficient (caches results more) to avoid regen delay when tabbing to it (also improved tab speed with the Inventory tab)BUGFIX: repaired...