Merge pull request #371 from kpdecker/benchmarks

Add benchmark coverage for all $ APIs
Merge pull request #369 from kpdecker/reduce-intermediate

Reduce intermediate object creation
Fix bug in `siblings`

Do not consider siblings' contents when filtering
Fix bug in `prevAll`

Do not consider siblings' contents when filtering.
Implement `selector` argument of `prev` method
Fix bug in `prevUntil`

Do not consider siblings' contents when filtering.
Implement `selector` argument of `next` method
Fix bug in `nextAll`

Do not consider siblings' contents when filtering.
Fix bug in `nextUntil`

Do not consider siblings' contents when filtering.
more keywords
it's -> its

Can't get any more trivial than that
Merge pull request #379 from dandv/patch-1

it's -> its
pin entities to <0.4
Merge pull request #382 from globin/pin-entities

pin entities to <0.4
Merge remote-tracking branch 'upstream/master'