fixing relative l0
Merge branch 'master' of https://github.com/meduz/SparseEdges

* 'master' of https://github.com/meduz/SparseEdges:
  logging fix
  fixing firstorder
  re-running firstorder

Conflicts:
	SparseEdges-tests.ipynb
	SparseEdges.ipynb
	prior.ipynb
 forking prior notebooks