When use where more than once on the same column, relation doesn't do an 'or' or 'in' with the values

Fix bug with 0bb85ed9 which missed out a fixtures declaration in cascaded_eager_loading_test.rb

reloading an association will properly set attributes of instantiated objects. Thanks Brian Palmer [#5802 state:resolved]

[#5978 state:committed]

if association is already loaded and if a find operation is performed on the already loaded association list with an empty hash then do not perform another sql

[#5972 state:resolved]

Fix bug where size of through association is not correct after adding a has_many association (occurs only before main object has been reloaded).

[#5968 state:committed]
Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

Fixed bug in active_record/nested_attributes where an empty string id caused an ActiveRecord::RecordNotFound error. Found by [Ben Tillman]

[#5638 state:committed]
Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

- persisted? is the API defined in ActiveModel
- makes it easier for extension libraries to conform to ActiveModel APIs
  without concern for whether the extended object is specifically
  ActiveRecord

[#5927 state:committed]
Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

use column names as order by complex function parameters, fix for postgresql adapter to correctly remove ASC/DESC
Signed-off-by: NSantiago Pastorino <santiago@wyeworks.com>

Fixes queries using limits and punctuation in order, removes order("col1, col2") usage in favor of order(["col1", "col2"})

[#4597 state:committed]

Convert :primary_key in association to a string before comparing to column names, so that for example :primary_key => :another_pk works as well [#5605 state:resolved]