entity_dependency 7.x-1.0-alpha2

Changes since 7.x-1.0-alpha1:

• #1538848 by ianthomas_uk, Sergii: Fixed EntityMalformedException: Missing bundle property on entity of type node.
• Manually re-rolled the iterator-plugin branch since it turns out it was completely busted. Also made some logical changes.
• Revert "Make the Entity Dependency Iterator pluggable"
• Make the Entity Dependency Iterator pluggable
• #2137187 by skwashd: Fix (most) issues found by coder-review
• #2051811 by microhate: File support.
• #1920054 by jneubert: Handle dangling references to deleted entities (especially taxonomy terms).
• #1545278 by sea4, David_Rothstein, bricel, microhate, maciej.zgadzaj: Dependencies are not added for entityreference fields (Symptom: Undefined index: target_type()).
• #1970760 by reevo: EntityDependencyIterator does not keep track of revision_id().
• #1535520 by Stalski: Added Image avatars should be seen as entity dependency.
• #1429596 added field collection support.
• Improved iterator algorythm.
• #1429594 by neochief: Fixed Imagefield dependencies.
• #1427810 by neochief: Fixed Wrong key in dependency checker.
• Changed name on the 'origin' functionality, to be 'cause'. Still fuzzy, but makes more sense
• Fixed a bunch of E_STRICT notices in the iterator.