[TASK] Add support for custom property mapping for object

This change add a new Interface "TargetMappingInterface" for Transformer
class. Transformer class can implement a method getTargetMapping who return
an array to configure the mapping for a object mapping type.

See: https://gist.github.com/dfeyer/3a94dd2527eabefba19e
[TASK] Add support for ElasticSearch Repository and Query abstraction
[TASK] Fix PHPdoc comment
[TASK] Store raw ES response in the Query object
[TASK] Initialize an GenericType object in the Repository
[TASK] Add support for default sorting and query limit (size)
[TASK] Add support for custom raw query
[TASK] Do not store DocumentType name in Repository use only DocumentType
[TASK] Remove var_dump
[TASK] Add query boost support