Re-fix hud_change stat argument retrieval

Conflicts:
	src/script/lua_api/l_object.cpp
Add curl, freetype and luaJIT to CMAKE_BUILD_INFO
Lower the default max_users from 100 to 15
Show git hash in version string at top left corner of window
Remove doc/gpl-2.0.txt, add doc/lgpl-2.1.txt
Add --version option
Allow to manually specify param2 in minetest.item_place() and return success
Add set_name(), set_count(), set_wear() and set_metadata() to Lua ItemStack
Pass VERSION_EXTRA to GenerateVersion.cmake
Optimized minetest.get_connected_players()

Instead of collecting all objects within a huge radius (which could be
a big value), just register each player that connects and give back the
current hold list.
Remove mapgen_air alias (#935)
FIx wrong error message on invalid use of the formspec element image_button
Add Czech language
Translated using Weblate (German)
Translated using Weblate (French)
Translated using Weblate (Dutch)
Translated using Weblate (Chinese (China))
Translated using Weblate (Portuguese (Brazil))
Translated using Weblate (Dutch)
Translated using Weblate (Portuguese (Brazil))