Add meshnode drawtype.
Move buttons upwards to accommodate for new configure keys button in the
pause menu
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
Merge remote-tracking branch 'minetest/master'

Conflicts:
	src/client.cpp
	src/nodedef.cpp
Custom collision boxes node property.
Merge remote-tracking branch 'minetest/master'
Fix memory leak caused by mesh nodes (and nodeboxes)
Fix some indentation in nodedef.cpp
Merge remote-tracking branch 'minetest/master'

Conflicts:
	src/nodedef.cpp
Merge remote-tracking branch 'upstream/master' into next

Conflicts:
	src/mapblock_mesh.cpp
	src/nodedef.cpp
	src/nodedef.h