Copy-pasting chunks of a level

[ramnes]

When editing a level, a big pain is that you can't create something and replicate it.

For example, if I'm building conference rooms and want three of these, I have to build every single conference room; it would be much nicer if I could create one and then copy-paste it.

[ramnes]

I've just realized that you can copy a 1x1 chunk with shift-click! So we just need to add the support for long clicks, that would select a zone while shift stay pressed. :)