Properities should not be required for object as elastica can automap
Adding new persister and new transformer to make use of the serializer support of elastica when persisting doctrine objects
Tests for new provider and new transformer
renaming services to avoid potential conflicts
some formatting and cleaning up
refactoring some code
fix typos
clean ups
Merge remote-tracking branch 'origin/serializer-transformer' into serializer-integration

Conflicts:
	DependencyInjection/FOSElasticaExtension.php
	Resources/config/config.xml
Merge remote-tracking branch 'peerj/ObjectWithoutProperties' into serializer-integration

Conflicts:
	Transformer/ModelToElasticaAutoTransformer.php
Replace deprecated calls `Document::add` to `Document::set`
Allow empty or null or no `mappings:` key under type configuration

refs #300. This commit allow to define types without having to
set any mapping as Elasticsearch build his own.

The minimal config become:

    indexes:
        toto:
            client: default
            types:
                Article:
                    mappings: ~
                    ...
Ref #341, fix the insertMany method to use Bulk indexing

To make it works, I inject the serializer defined for the Type
into the fos_elastica.object_serializer_persister service.

This is the SAME service injected in the setSerializer of Type.

We deport the handling of serialization outside Elastica,
this is not so good but we need to build our own Documents to
get the ID's correctly.
Remove extra line-break
Fix Persister constructor and undefined property
Add UPGRADE-3.0.md file with descriptions of new features / changes
Adds enabled mapping option (default true)
Merge pull request #418 from blongden/2.0.x

Adds enabled mapping option (default true)
Merge branch '2.0.x' into 2.1.x
Merge branch '2.1.x'