Do not call adapter.deleteRecord for a record that is already saved and deleted.
Remove DS.AttributeChange.
Allow belongs to associations to be saved when the associated object is null.
Remove accidentally added capitalize and camelize
Copy metadata when it is assigned to recordArrays

Currently metadata is saved on Model classes, such that there is
only ever 1 instance of the meta object in existence. Often however
metadata is a property of a particular array of records and not the
record type. A good example is pagination. It should be possible to
do `store.findQuery()` twice and get two arrays where each has it's
own meta information. However, because metadata is stored on the
Model class, any subsequent request will modify the original
pagination metadata. This commit enables each recordArray to have
it's own unchanging Meta object.
DS.EmbeddedRecordsMixin methods for serializing relationships call super if needed

[Fixes #1971]
[Docs] Update documentation for the EmbeddedRecordsMixin
Merge pull request #1967 from emberjs/metadataCopy

Copy metadata when it is assigned to recordArrays
Merge pull request #1671 from bmac/delete-saved-record

RESTAdapter suppress DELETE request when deleted record has already been saved
Merge pull request #1972 from pixelhandler/embedded-mixin-calls-super

DS.EmbeddedRecordsMixin methods for serializing relationships call super
Cleanup embedded docs
Add failing test for hasMany relationships

If adapter does not return any data for a hasMany relationship,
the unsaved hasMany records disappear from the relationship.
Fixes #1466
Always keep the hasMany around when payload arrives

We should always keep the current hasMany value if the payload
has no relationships with that key
Fixes hasMany records being duplicated after payload returns from server

There is an edge case where a hasMany record gets duplicated (same ID).
Basically, if we generate a record locally using UUID or any custom ID
format, then push it to production which will return the same ID
previously defined, the store's array that holds records to be resolved
is going to duplicate both items, even if they have the same ID.

This commit fixes that by not allowing duplicated IDs in that array.
fix merge conflicts
v1.0.0-beta.8 Changelog
remove CHANGELOG cruft
changelog cleanup
Merge pull request #1969 from pixelhandler/ember-records-mixin-docs

[Docs] Update documentation for the EmbeddedRecordsMixin