[MultiBuild] Add visual indicator of centered item when placing

[decairn]

Highlight the blueprint reference building when pasting so that easy placement can be done; just pick a different color from the red/blue that the rest are. This reference is often made by those who publish blueprints, and on larger ones it will really help ease the placement.

[brokenmass]

when pasting the reference building is always the one on your cursor. why would you need another visual indicator ?

[decairn]

Oh it does? I didn't realize. I re-read the docs and see its mentioned on the blueprint creation bit (which I obviously didn't read) and not the pasting bit. Closing this.