Fixes backwards notifications for values and relationship notifications.
Post notification for AFIncrementalStoreContextWillFetchNewValuesForRelationship.
Refresh destination object when an insert fails, prevent dangling relationships.
Don't try to insert a nil object to the array.
Merge pull request #223 from baarde/skip_fault_relationships_update

Skip relationships that are fault when updating backing object with managed object
Merge pull request #221 from Spaceman-Labs/bugs/dangling_relationship

Prevent dangling relationships when an insert save fails
Minor refactoring
Merge pull request #220 from Spaceman-Labs/bugs/notifications

Fix reversed context notifications
[Issue #217] Using backing object ID cache
Merge branch 'master' of https://github.com/AFNetworking/AFIncrementalStore
[Issue #212] Reverting to use of constant value for incremental node, rather than absolute time
[Issue #109] Prevent records from being requested excessively
Removing manual context merge from notification center observer
Removing another manual context merge from notification center observer, which had caused infinite loop of relationship fetching
Merge pull request #213 from baarde/master

Fix a dangerous usage of error pointer
Merge branch 'master' of https://github.com/AFNetworking/AFIncrementalStore
Bumping version to 0.5.1
Merge remote-tracking branch 'AFIncrementalStore/master' into backing_encapsulation

Conflicts:
	AFIncrementalStore/AFIncrementalStore.m

Changes from 6f2b1d07f65b89b4624345045bf27ac19349f8c9 were reverted as caching is done by AFIncrementalBacking
Merge branch 'backing_encapsulation' into develop
Merge branch 'resource_identifier_on_insertion' into develop

Conflicts:
	AFIncrementalStore/AFIncrementalStore.m