Fix #5990

* remote:
  move fanout back to a global variable, add a mutex for safety

Refactor db:structure:dump task.

Remove extra test case.

Make the test description better reflect what is happening

Rename testcase name. It's wrong in the context.

Rename MySQLTestPurge to MySQLPurgeTest for consistency.

Refactor db:charset task

In a similar vein to Pat's work on create, drop etc, the db:charset
task is now a one liner in databases.rake

Added test for case when view doesn't have logger method when using 
ActionController::Metal controller.

Ensure that cache-control headers are merged

Added test for case when view doesn't have logger method when using ActionController::Metal controller.

Closes #6675

This happens when A has_many many B and A accepts_nested_attributes B that has a numeric colum
with initial 0 value. So a.update_attributes({:b_attributes => { :id => b.id, :numeric => 'foo' }})
passes the validation test but, the value of :numeric doesn't change.
his commit forces that the update fails with the above conditions.

Fixes #6393
Fixes #2331

Added `stored_attributes` hash which contains the attributes stored using
ActiveRecord::Store. This allows you to retrieve the list of attributes
you've defined.

    class User < ActiveRecord::Base
      store :settings, accessors: [:color, :homepage]
    end

    User.stored_attributes[:settings] # [:color, :homepage]

This allows you to retrieve the list of attributes you've defined.
Usable for e.g. selects in the view, or interators based on the
attributes you wish to store in the serialized column.

The problem:
Accessing a HashWithIndifferentAccess does not return the the same object
that is stored in the hash (i.e. equal?) causing unexpected results:

    hash = HashWithIndifferentAccess.new {|h, k| h[k] = []}
    hash[:a] << 1  # => [1]
    hash[:a]       # => [], expected [1]

The cause:
When a block is provided to generate default values the generated values
are duped if they are arrays. The duped value is stored in the hash but
the original value is returned when the hash is accessed.

The fix:
The duping is there for allowing frozen arrays containing hashes to be
modified. The fix restricts the duping to this case. Note that if default
function generates a frozen array an error will be raised on assignment
before and after the patch.

Closes #3811

make events not use date and time to determine parent_of. fixes #5932