Various uninitialised variable fixes

sky.cpp: m_bgcolor.getAlpha() was being used before initialised

mesh related: m_highlight_mesh_color was being used uninitialised
Update the cURL the buildbot uses to 7.38.0
Custom collision boxes node property.
Fix memory leak caused by mesh nodes (and nodeboxes)
Fix some indentation in nodedef.cpp
Recalculate normals for cached meshes.

Check if mesh is here before adding to meshcollector.

Fix deleting the meshes.
Search for subgames using $MINETEST_SUBGAME_PATH.
Translated using Weblate (Japanese)
Add Indonesian Language
Fix broken plantlike drawtype.
Fix syntax error in Japanese translation
Remove remenants of mob code

Since minetest has no mobs within the core anymore, I suppose these
settings and code should go. Any mod that uses `minetest.setting_getbool`
will work with no problem since the default return value is `false`.
Remove m_ext_ptr in GUIFormSpecMenu, replaced by refcount mechanism
Add NodeResolver and clean up node name -> content ID resolution system
Add support for eased 3d noise
Change license of noise implementation to Simplified BSD
Prevent invalid memory access under failure conditions
Add NodeResolver documentation

Set content to fallback on AddNode failure
Consider node list requests with no results as failed
Add notice when only minimal is installed
Fix #1733: An unhandled exception occurred: GetPeer: Peer not found (possible timeout)