Add test case for scaffold_controller generator without attributes.

This is a test for 978c568a7bffe354180aaefa471092182fed1015
Use the references and belongs_id ids in the scaffold_controller
generator
Use `File.expand_path` instead of `File.join`

cc/ @carlosantoniodasilva
Put the reference and belongs_to attributes in the scaffold tests.
Make references and belongs_to attributes to generate the _id column in
fixtures
Deal with polymorphic attributes correctly in the generators
Extract a attributes_names method to avoid duplication
Add GeneratedAttribute#column_name to get the name of the column in the
database
Merge pull request #8472 from schneems/schneems/expand_path

Use `File.expand_path` instead of `File.join`
Ensure the scaffold tests will pass when using references attributes
Merge branch 'scaffold_fixes'
Fix decorating columns for serialized attributes
The return value from mailer methods is not relevant.
Merge pull request #8441 from itzki/fix_decorate_columns

Fix decorate_columns for finding only non-serialized columns
Merge pull request #8450 from senny/8448_mailer_return_values

the return value of mailer methods should not be relevant
Prevent raising EOFError on multipart GET request.

Such request can happen on Internet Explorer. When we redirect
after multipart form submission, the request type is changed
to GET, but Content-Type is preserved as multipart. GET request
cannot have multipart body and that caused Rails to fail.

It's similar fix to Rack's one:
https://github.com/chneukirchen/rack/blob/8025a4ae9477d1e6231344c2b7d795aa9b3717b6/lib/rack/request.rb#L224
Merge pull request #8476 from sheerun/fix/multipart-get

Prevent raising EOFError on multipart GET request.
Move new CHANGELOG entry to the top
Added regression test for #8195.
Make sure the tests pass in the case closer to described in #8195

Conflicts:
	activerecord/test/models/bulb.rb
	activerecord/test/schema/schema.rb