Optimize filter with selector

Test: traversing - Parent (file: jquery.html)
  cheerio x 8,651 ops/sec ±11.22% (62 runs sampled)
  jsdom x 6,835 ops/sec ±12.34% (68 runs sampled)
  old x 442 ops/sec ±10.25% (65 runs sampled)
  Fastest: cheerio

Test: traversing - Parents (file: jquery.html)
  cheerio x 25.36 ops/sec ±17.24% (36 runs sampled)
  jsdom x 101 ops/sec ±13.70% (57 runs sampled)
  Fastest: jsdom

Test: traversing - Closest (file: jquery.html)
  cheerio x 58.91 ops/sec ±13.71% (55 runs sampled)
  jsdom x 126 ops/sec ±13.47% (63 runs sampled)
  old x 6.35 ops/sec ±14.50% (21 runs sampled)
  Fastest: jsdom

Test: traversing - Filter (file: jquery.html)
  cheerio x 5,497 ops/sec ±14.45% (54 runs sampled)
  jsdom x 6,233 ops/sec ±18.27% (56 runs sampled)
  old x 179 ops/sec ±42.74% (48 runs sampled)
  Fastest: jsdom

Test: traversing - Children (file: jquery.html)
  cheerio x 1,627 ops/sec ±14.94% (50 runs sampled)
  jsdom x 243 ops/sec ±16.94% (51 runs sampled)
  old x 217 ops/sec ±12.39% (54 runs sampled)
  Fastest: cheerio
Use strict equality rather than falsy check in eq
Avoid unnecessary indexOf from toggleClass
Merge branch 'reduce-intermediate'
Merge branch 'filter-perf'