Added symfony/config package
Added symfony/yaml package
Added Yaml loader
Created MappingFactory
Moved configuration from DIC
Fixed Factory
PathUnit -> TokenProvider
Used file locator to locate resources

This allows people to configure their paths using the @xxxBundle notation
and it allows overriding files in the app/Resources directory.
Updated to token providers
Started with the XML loader
Included jms/metadata
Integrated JMS Metadata
Added test for MetadataFactory + ClassMetadata
Removed TokenProvider class and updated yml format
Implement extend
Added extend merging
Fixed circular detection
Changed %% to {} and $schema to {parent}
Implemented XmlFileLoader
Massive refactoring

- Droped per token/provider exists/not_exists
- Abstracted all database logic to driver
- URLs now treated as entire URLs, not they're component parts
- Support for handling old routes