* Modernize source code: last par
* Use empty when needed
* Use emplace_back instead of push_back when needed
* For range-based loops
* Initializers fixes
* constructors, destructors default
* c++ C stl includes
Adds the possibility to colorize item stacks based on their metadata.
In the item/node definition you can specify palette (an image file)
and color (fallback color if the item has no palette or metadata).
Then you can add palette_index to the metadata.
Dropped itemstacks with different colors do not merge.
