Remove `argCount` from `_.callback` and add `getCallback` helper.
Add `_.matches` benchmark.
Add fast path for objects with a single primitive value back to `_.matches` and add `isStrictComparable` helper to reduce `_.matches` and `_.isEqual`.
Merge branch 'master' of github.com:lodash/lodash
Tweak `_.isXyz` method docs. [ci skip]
Make `_.isArguments` fallback align with other array-like checks.