Show warning message if delete_all is firing callbacks

`post.comments.delete_all` will fire callbacks if :dependent option is
:destroy . It will be fixed in Rails 4.1 . In the meantime display
a warning . Look at #9567 for details .
Merge pull request #9668 from neerajdotname/9567-delete-all-warning

Show warning message if delete_all is firing callbacks
documents how to DROP DEFAULT [ci skip]
quick pass over the RDoc of schema_statements.rb [ci skip]
promotes change_column_null to the migrations API
dependent: :destroy should call destroy_all

Commit https://github.com/rails/rails/pull/9668 shows warning
when `delete_all` is invoked with `:dependent` option
`:destroy`.

Unfortunately invoking `Post.destroy_all` invokes
`post.comments.delete_all` as part of `has_many` callbacks.

This commit ensures that instead `post.comments.destroy_all` is
invoked and in the process no warning is generated.

See issue #9567 for details .
Fix typo [ci skip]
Fix typo in DependenciesTestHelpers module name
Pass column to quote when copying a sqlite table.

To make quote escape binary data correctly it needs the column passed in.
Merge pull request #9681 from vipulnsward/fix_typo_in_module_name

Fix typo in DependenciesTestHelpers module name
Merge pull request #9615 from mmb/copy_table_binary_sqlite

Pass column to quote when copying a sqlite table.

To make quote escape binary data correctly it needs the column passed in.
Merge pull request #9676 from neerajdotname/9567-destroy-should-call-destroy-all

dependent: :destroy should call destroy_all