Minetest 5.13.0

What's new in this version:

Deprecations and compatibility notes:
- Vectors passed to C++ API functions may no longer have nil components.
- This change can reveal logic issues within mods.

Client / Audiovisuals:
- 9-slice formspec image buttons now display correctly with gui_scaling_filter
- Fixed an issue where main menu dialogs could overlap upon start
- Tabs in formspecs can now be changed using Ctrl(+Shift)+Tab
- The formspec element model[] now supports floating-point frames
- The minimap now correctly displays drawtype = "air" nodes
- Main menu ContentDB usability improvements
- Meshgen (i.e. visible mapblocks) code cleanups and improvements
- Add keybinding for world close key (keymap_close_world)
- Relaxed path checks in the main menu to allow downloading mods to symlinked directories

World / Server / Environment:
- The Luanti version is now printed after the ASCII logo
- Fix main menu hang caused by dropped DNS packets
- Fix newline conversion in formspecs on Windows (copy & paste)
- Fix crash caused by empty particle spawner texture

Script API / Modding:
- Various lua_api.md improvements
- Empty Voxel Manipulators can be created using VoxelManip:initialize()
- Fixed an issue where sizeless text input formspecs would incorrectly send ExitButton as text
- core.show_formspec now allows showing a player inventory
- core.get_node_raw is now a public API
- New API function core.get_mapgen_chunksize()
- Newly spawned entities now have a persistent GUID, see ObjectRef:get_guid()

Misc / Maintenance:
- Many various code improvements and cleanups
- Improved unit tests
- Model skeleton animation cleanups, test and documentation
- Header files are now added as CMake sources (useful for Visual Studio (Code))