linus suggested mods

makes sense.
comments and newline
Set __package__ in data_structure to correct value
Merge branch 'refactor' of https://github.com/nortikin/sverchok into refactor
shouldn't break anything, but does need testing.
version bump for bmesh viewer bpy.ops removal
Frame change handle setting in pref
small cleanup to silence pep8
Better keep the .utils I guess
Merge branch 'refactor' of https://github.com/nortikin/sverchok into refactor
centre polygons node, zip node, mesh separate node fixed, centers rebuilded completely
Merge branch 'refactor'