Some refactoring
Remove circuit nodes duplicates from games/minimal/mods/default/init.lua
Remove circuit elements textures duplicates from games/minimal/mods/default/textures/
Initial support of 6d facedir + some refactoring.
Bug fixes + Some refactoring.
Add license headers
Add more circuit elements
Disable preload_item_visuals by default

This can delay connections by several minutes.
Formspec escape fixed seen in world creation menu
Replace jmutex with std::mutex
replace JMutexAutoLock with std::unique_lock<std::mutex>
Fixed Windows VS build.
Try link with opengles1 lib
Merge remote-tracking branch 'minetest/master'
remove second preload_item_visuals
Merge remote-tracking branch 'upstream/master' into next
Fix ogles2 shaders path without android
Fix ogles linking order
Move #includes from version.h to version.cpp
Do not use std::timed_mutex