This can still be added to the middleware stack, but is really not
necessary.  I'll follow up with a commit that deprecates the constant

* pp:
  remove outdated comment
  all parameter parsing is done through the request object now.
  let the request object handle parsing XML posts
  remove setting request parameters for JSON requests
  remove the request parameter from `parse_formatted_parameters`
  do not instantiate a param parser middleware
  push the parameter parsers on to the class
  stop eagerly parsing parameters
  only wrap the strategy with exception handling
  pull `normalize_encode_params` up
  remove the `default` parameter from the parser method
  move parameter parsing to the request object

all parameter parsing is done on the request object now, so we don't
need to worry about at ParamParser middleware

The test request object will handle parsing XML posts now, so we don't
need to eagerly parse them in the test harness

The request object will automatically parse these in the
`parse_formatted_parameters` method, so we don't have to worry about it.

This is an instance method on the request object now so we don't need it
anymore

we don't actually need a param parser middleware instance since the
request object will take care of parsing parameters for us.  For now,
we'll just configure the parameter parsers on the request in this class.

Include interpolation values to translation_missing helper

Added test for `any` if called without specifying any format

The middleware stack is a singleton in the application (one instance is
shared for the entire application) which means that there was only one
opportunity to set the parameter parsers.  Since there is only one set
of parameter parsers in an app, lets just configure them on the request
class (since that is where they are used).

Parameters will not be parsed until they are specifically requested via
the `request_parameters` method.

we need to be more specific about exception handling when dealing with
the parse strategies.  The calls to `return yield` can also raise an
exception, but we don't want to handle that in *this* code.

`normalize_encode_params` is common to all parser code paths, so we can
pull that up and always apply it before assigning the request parameters

since there is only one "default" strategy now, we can just use the
block parameter for that.

All parameter parsing should be on the request object because the
request object is the object that we ask for parameters.

Example
````ruby
mail(hash) do |format|
  format.any
end
```` 

DRY enum conflict detection

Corrected `to_time` output in ActiveSupport Date Conversion docs [ci …

Corrected `to_time` output in ActiveSupport Date Conversion docs.Since https://github.com/rails/rails/commit/48583f8bf74d1cefefea3cd6591bd546a9eaff6c, to_time returns times formatted as YYYY-MM-DD HH:MM:SS UTC [ci skip]

`to_time` method now returns in `YYYY-MM-DD HH:MM:SS UTC` format.

[ci skip]

Correct ArgumentError message in ActiveSupport conversions docs [ci s…

This was happened after this commit https://github.com/rails/rails/commit/2ebf47aea21ff8ac10681e53e78dd7a0e5c31c6e

Change AbstractRequest to ActionDispatch::Request

AbstractRequest has been deprecated, updating to refer to ActionDispatch::Request instead.

[ci skip]

When used by ActionMailer, ActionView should automatically use the correct MIME type just as it does when used by ActionDispatch

Improve Docs of ActiveSupport::TimeZone [ci skip]

Fix displaying mailer previews on non local requests.

[ci skip] Remove useless "@api public/private"

Fixed helpers submit button Examples [ci skip]

`restrict_with_error` message will now respect owner’s human name

Other public APIs do not have these annotations.

When config `action_mailer.show_previews` is set, previews are displayed
regardless of local request check.