Fix bug/typo in benchmark
Add `appendAll`, `prependAll`, `afterAll`, `beforeAll` methods

These methods act the same as (resp.) `append`, `prepend`, `after`,
and `before`, but accept an array of children/siblings instead
of a single one.

This allows these methods, internally using the new `insertAll`
method, to work slightly faster by optimising loops.

These methods improve performance by roughly 16% on large-scale
operations.
Merge branch 'feature/add-insert-all'
Update eslint
Update changelog for 0.4.0-rc.2
0.4.0-rc.2