Attribute mapping proof of concept
Merge branch 'master' of https://github.com/refactorthis/GraphDiff into dev
Multiple refactors and implementation of new features

 - Added support for UpdateParams to allow for configuration per update operation
 - Started a refactor of some components into smaller single responsibility objects (QueryLoader, AttributeGraphBuilder)
 - Added support for QueryMode though NOT IMPLEMENTED for multiple queries as yet
 - Added stubs for support of caching ConfigurationMappings -> NOT IMPLEMENTED
Refactor: pulled change tracker and entity manager out of the GraphNode.

 - Added entity manager, change tracker
 - Added support for multiple query modes
 - Added support for fluent API and mapping schemes.
Refactor and updates for attribute mappings

 - Refactored UpdateParams, pulled mapping out into extension method as it was easier to use
 - Ensured cyclic graph traversals are not attempted when reading attributes
 - Add a property on the attribute to mark the aggregate root
 - Added tests around Fluent mapping scheme configurations
Cleanup - Add xmldoc comments, rename ConfigurationVisitor for consistency with other graph builders.
Merge branch 'master' of https://github.com/refactorthis/GraphDiff into FluentAttributesRefactor
Merge pull request #69 from refactorthis/FluentAttributesRefactor

Fluent & Attribute configuration support, caching, compositional refactor, query mode