Added rollback method to ActiveModel::Dirty
Rename options param of #time_ago_in_words to match API change

Rename `include_seconds_or_options` to `options` to match 6b9356a (which removed the deprecation introduced by #6077).  This has no functional impact because the parameter is passed directly through, but makes it clearer that the parameter no longer supports a boolean as input.
Always pass a column with a type object to quote

The only case where we got a column that was not `nil`, but did not
respond to `cast_type` was when type casting the default value during
schema creation. We can look up the cast type, and add that object to
the column definition. Will allow us to consistently rely on the type
objects for type casting in all directions.
Merge pull request #15962 from sgrif/sg-types-for-defaults

Always pass a column with a cast_type to quote
Merge pull request #15961 from mckramer/patch-1

Rename options param of #time_ago_in_words to match API change
Quick pass through Active Support and guides CHANGELOG

[ci skip]
Tiny documentation fixes [ci skip]
Don't encourage usage of `columns_hash`

As discussed in https://github.com/plataformatec/simple_form/pull/1094,
we should not encourage usage of `columns_hash`, and instead provide an
alternate method to determine whether or not an attribute exists.

The language `attribute` was chosen over `column` since these are in the
`AttributeMethods` module.
Use the type object for sending JSON to the database
Add `Hash#map_values` to ActiveSupport

Didn't get a chance to convert existing code, I'll skim through the code
base to make use of this later this afternoon.
Merge pull request #15819 from sgrif/sg-hash-map-values

Add `Hash#map_values` to ActiveSupport to simplify a common pattern
Simplify creation of default attributes on AR instance

`AttributeSet#dup` has all the behavior we need.
Merge pull request #15979 from sgrif/sg-json-quoting

Use the type object for sending JSON to the database
Use `Hash#transform_values` to clean up `AttributeSet`
Merge pull request #15982 from sgrif/sg-attr-set-map-values

Use `Hash#transform_values` to clean up `AttributeSet`
Use the type object when sending point columns to the DB
Merge pull request #15976 from sgrif/sg-attribute-exists

Don't encourage usage of `columns_hash`
Merge pull request #15983 from sgrif/sg-inline-point

Use the type object when sending point columns to the DB
Remove array workaround in PG quoting

We no longer need to do fancy legwork to make sure arrays use a type
object, now that schema methods use a real type object.
Remove unused `array_member` from PG quoting for HStore columns

Hstore no longer needs additional quoting to be used in an array, the
array type handles it sufficiently.