Mgv5/mgv7: Remove 'should make cave hole' feature
Remove ravine code

Replaces while loops with proper getfield calls

The Irrlicht engine supports antialiasing, and Minetest already supports
saving an antialiasing setting in its configuration file.  However,
Minetest lacked UI elements to set this setting, and previously the only
way to enable the feature was by hand-editing the configuration file.

Add a drop-down menu that can enable antialiasing.

The doc and the actual behaviour differed.

Change the name for texture pack description files from "info.txt" to "description.txt" in order to keep the naming consistent between description files for both mods and texture packs.

Also add backwards compatibility for texture packs that use "info.txt", and note in the log that "info.txt" is depreciated.

Currently translated at 100.0% (269 of 269 strings)

Currently translated at 100.0% (264 of 264 strings)

Currently translated at 100.0% (264 of 264 strings)

Currently translated at 1.7% (4 of 235 strings)

Currently translated at 100.0% (264 of 264 strings)

Currently translated at 99.1% (233 of 235 strings)

Currently translated at 82.5% (194 of 235 strings)

Also don't show "probably running a different version" message in simple singleplayer mode

Improve TOCLIENT_ACTIVE_OBJECT_MESSAGES robustness for handling invalid data

Add serializeHexString()
Clean up util/serialize.cpp

Fix 'is ground content' for some nodes

- Stop attempting to start a world when no world's created/selected in server tab
- Better world's indexes handling between subgames lists

Spare some copies.

The neighbours checked are the 8 nodes horizontally surrounding the decoration base
and the 8 nodes horizontally surrounding the ground node below the decoration

Use wide_to_utf8 and utf8_to_wide instead of wide_to_narrow and narrow_to_wide at almost all places.
Only exceptions: test functions for narrow conversion, and chat, which is done in a separate commit.

- Fixed race conditions
- Fixed null dereference
- Fixed out-of-bounds array access
- MinimapMapblock is now allocated and added to update queue only when enabled
- Removed dependency on LocalPlayer
- Fixed code style
- Simplified expressions and program logic
- Cleaned minimap object interfaces

Lowest level of base terrain determines mountain generation in mapchunk
Change some positional function arguments from int to s16