CODE: bbox based centering
WIP: biomol supprt for cylinder shader
UPDATE: OBJLoader from three.js
CODE: adapted surface handling
WIP: biomol support, buffer refactoring
Merge branch 'dev' of https://github.com/arose/ngl into dev

Conflicts:
	js/ngl.js
WIP: buffer refactoring
WIP: buffer refactoring
FIX: backbone repr coloring may fail
FIX: backbone repr fails for 1 residue fibers
FIX: hyperball drawn as licorice (when impostors are disabled) not updatable
FIX: picking may fail
CODE: minor enhancements
FIX: BufferVectorHelper
FIX: shading seems in CylinderGeometryBuffer from wrong normals
WIP: render unlit background group
Merge branch 'dev'