fixes #1548: _.initial broken for n > array.length
Merge pull request #1549 from michaelficarra/GH-1548

fixes #1548: _.initial broken for n > array.length
Use deepEqual when appropriate.
Merge pull request #1550 from braddunbar/deep-equal

Use deepEqual when appropriate.
Remove comment missed in #1525

Remove comment on using `nativeIndexOf`
Merge pull request #1553 from megawac/patch-1

Remove obsolete comment about using native indexOf
define _.contains for array-likes in terms of _.indexOf
Merge pull request #1556 from davidchambers/contains

define _.contains for array-likes in terms of _.indexOf