v0.2.17

• PATCH: a new optional field, new exports and a fix, with no break. The packing engine found the 2 gaps when it moved to 0.2.16.
• The new exports are shapeLevel, ShapeLevel and ShapeBound. MeasureSpec and ShapeSupport have the new optional field bound.
• bound lists the kinds where the value of a measure is a bound of the true value, and its side upper or lower. An example is a fill that reads w * h of a free box.
• shapeLevel(use, kind) gives exact, safe, bound or none. ruleLevel does not read bound, and its result stays the same.
• By default, checkShapes refuses a bound kind. Its break tells the side, for example "The value of pack.shapeFill is only an upper bound for free".
• ShapeCheck.level has the new value bound. It accepts the exact, safe and bound kinds. The level safe accepts the exact and safe kinds only, as in 0.2.16.
• shapeSupportProblems refuses a kind in two of the lists shapes, safe and bound.shapes. It also refuses an unknown kind, a repeated kind and a bad side.
• docs/SHAPES.md tells what a bound value proves for each direction of a measure, and why the level is bound and not safe.
• Fix: with meta: "sample" and shapes, a sample does not throw for a meta option without a member list. It draws again, as spaceSize gives that option 0.
• A sample throws a RangeError only when the space has no config for the kinds. The error names the kinds, the stages without an option and the meta options without members. For such a meta option, it tells to set members.view to "bounds".
• Each sample that 0.2.16 gave stays the same, byte for byte. A test pins the samples of 0.2.16 for 8 spaces.
• Each input, manifest, record, hash and configId of 0.2.16 stays the same. JOINT_MEASURES has no bound.