v2.7.0

Changed

• Improved efficiency in packing and weight distribution
• Major internal refactoring. The public-facing API did not change in any incompatible ways, but if you extended any of the @internal classes or made use of @internal methods you may be affected.
• Bail out earlier in the packing process where an item doesn't fit [colinmollenhour]

Fixed

• Fixed potential issue where custom constraints might not be fully respected
• Avoid divide by zero error when a box is specified to have a depth of 0mm (e.g. 2D packing)