_.property support for null and undefined
Added Array created in another document test
Added support for arrays created in different document for `_.isEqual`
Removed the areArray check from the already convoluted `if` check for clarity as suggested by @jdalton
Implement _.isError
Enable max/min fast path for all non-iter cases
Merge pull request #1742 from megawac/min-max-fast

Enable max/min fast path for all cases with no iterator
Use rawgit for linking to old versions of docs
Merge pull request #1745 from megawac/rawgit-docs

Use rawgit for linking to old versions of docs
use cdn.rawgit.com instead of rawgit.com
Fix usage of hash function in `_.memoize`.

The function `_.memoize` has a bug where the first argument to the
function is used as the key when retrieving a result from the cache,
ignoring the hash function.

The fix is always to use the computed `address` as the key to the cache.

Confirmed the regression and fix with the updated unit test.
use non-capturing group in _.escape regex

https://github.com/jashkenas/underscore/pull/1740#commitcomment-7002658
Fix regression in max/min
Merge pull request #1749 from megawac/min/max-reg

Fix edge-case regression in max/min
Minor comment nits

[ci skip]
Merge pull request #1753 from d10/master

Minor comment nits
Don't use reserved property names in tests (ie<9 fails)
Merge pull request #1756 from megawac/reserved-keywords

Don't use reserved property names in tests
Keys shim misses non enumerable properties
keys shim: use enumBug flag