fixing potential issues
DAL: support identifiers with uppercase letters
Replace kernel container with dependencies
entity id property doc
Hooks: use only string to identify hooks
ORM: remove array implementation from EntityRelation
Core: kernel parameters accessors
Validation: 'in' rule validate method must be compatible with parent
Common\Bag: BagInterface
Migration: MigrationsManager db dependencies
Form: refactoring widgetsmanager
Container: parent class contract
Core: fixing bundle
Interfaces