Change large amount of objects to be configurable via a setting in minetest.conf (max_objects_per_block).

Play player_damage.ogg when recieving damage and additionally play player_falling_damage.ogg when recieving falling damage

Now Environment::clearAllObjects() unloads unused blocks in an interval
defined by max_clearobjects_extra_loaded_blocks (default 4096).

On the lua side, notably minetest.env:<function>(<args>) should now
be replaced by minetest.<function>(<args>).
The old way is and will stay supported for a long time.

Also:
Update and clean up lua_api.txt (by celeron55)
Move EnvRef to lua and remove add_rat and add_firefly (by kahrl)
Add separate src/util/CMakeLists.txt, other minor fixes (by kahrl)

Previously, when a block was activated, on_timer callbacks where
called with the relative position of the node inside the block,
instead of the absolute position of the node.

Add ServerEnvironment::setNode()/removeNode() to allow setting nodes from the C++ side with proper script-defined initialization/destruction

Send animations, bone overrides and attachments in entity initialization. Clients no longer have to be near an object when an animation or attachment is set to see the changes, and newly connected clients (or a client that simply renders the object for the first time) will get all of those settings. Therefore, the lua script no longer needs to run every X seconds either, just once per entity.

Finish fixing the material color code. But it won't work until MineTest has dynamic lighting... another day another feature.

Extra checks for the bone positioning / rotation code

Many checks and consistency improvements to the client attachment code

Make a separate function for checking if a client object is attached. A more in-depth change will be needed here to fix reading of invalid pointers

Use a different method of fetching the parent. Fixes the mass segmentation faults when rendering an attachment (some still happen though)

Major change to how attachments are handled. Fix the last segmentaton fault, which was due to the parent becoming invalid while being refreshed / removed which would bause the child to remain attached to nothing. Parents remove their children when being deleted themselves and add them back when re-added. Attachments are stored inside a 2D a vector which easily allows both a child to find their parent and a parent to find its children.

Remove attachment list entry when an object is being permanently removed. Also avoid duplicate entries in this list when re-attaching the same object

The "big code comments" can now go away. Client attachments almost work properly, and I know what else needs to be done