v4.0.0

Likely backwards-compatible, but it handles parents a little differently so to be sure this is released as semver major.

Changes

• Simplify code for array of parents: aa21f6e
• Properly handle parent-less select.all: 5f45ea4
• Short-circuit single-parent qSA out of the loop: a4b048a
• Drop .length cache in loop: 0333737
• Update dependencies: ef1f068