Memory usage optimization by not loading all pending versions

Conflicts:
	src/Pim/Bundle/VersioningBundle/Command/RefreshCommand.php
	src/Pim/Bundle/VersioningBundle/Entity/Repository/VersionRepository.php
	src/Pim/Bundle/VersioningBundle/Model/Version.php
Uses the provided getObjectManager() function
Add bug fix note on changelog
Fixes styles and version class fetching
Merge branch 'master' into fix/version_mem_leak

Conflicts:
	CHANGELOG.md
Merge pull request #1284 from akeneo/fix/version_mem_leak

Fix/version mem leak
Add an example line for MongoDB ODM config storage
PIM-2517 : introduce a _index_buttons template to ease overriding and
pass the locale object to this template
Merge pull request #1289 from akeneo/PIM-2517-product-grid-datalocale

PIM-2517 : introduce a _index_buttons template to ease overriding
PIM-2517 : use en_US as catalog locale for Julia in icecat demo datasets
PIM-2904: Avoid to delete or update the default user group
PIM-2904: Add the default to a user during its creation
PIM-2974 : move the smart datasource declaration
PIM-2904: Remove the "All" group from the list in the user edit form
PIM-2974 : introduce a request parameters extractor to wrap the
retrieving of parameters
Merge pull request #1291 from akeneo/PIM-2974

PIM-2974 : introduce a parameters extractor
PIM-2974 : use parameter extractor in in group filter
PIM-2974 : use parameter extractor in iss associated filter
PIM-2974 : update changelog
PIM-2904: Extract QB in repositories to clean user form