Added feature: Constrained shortest path is now built into the matlab class.
Merge remote-tracking branch 'origin/master' into dev
Removes error when displaying empty curve and potential unnecessary supergradient optimization.
Add unit tests for compute_visit_tree and verfiy reversed curves.
Adding ability to have empty curve stored in the curve obj.
Merge remote-tracking branch 'origin/unit_tree' into dev

Conflicts:
	matlab/unit_tests.m
Return running time for local optimization.
Cosmetics.
Fix erroneous assert in Curve_extraction.
Merge branch 'dev' of https://github.com/PetterS/curve_extraction into dev
Bug fix: Geodesic length.
Handling the voxel dimension inside the depth class.
Bug fix
Numerically more stable version of geodesic_length
Allow linear prog solution to run into max iter.
Adding test erroneously removed in an earlier commit.
Merge branch 'dev' of https://github.com/PetterS/curve_extraction into dev
Avoiding unnecassy declarations.
Temlating the cost functors.
Adding custom cache for torsion