Fix relief mapping issues

client/shaders/nodes_shader/opengl_fragment.glsl

client/shaders/nodes_shader/opengl_vertex.glsl

client/shaders/water_surface_shader/opengl_fragment.glsl

doc/lua_api.txt

games/minimal/mods/default/init.lua

src/client/tile.cpp

src/client/tile.h

src/game.cpp

src/mapblock_mesh.cpp

src/network/networkprotocol.h

src/nodedef.cpp

src/nodedef.h

src/script/common/c_content.cpp

textures/base/pack/disable_img.png

textures/base/pack/enable_img.png