Updated ModelToIdPropertyTransformer so it works with Entities which implement \ArrayAccess
Added FooArrayAccess class to allow testing of new code
See #2301
Updated logic and added Exception messages when an incorrect configuration is used.
#1723 added prototype for code like ``` $formMapper ->with('tab1', array('tab'=>true)) ->with('group1') ->add('username') ->add('password') ->end() ->with('group2', array('collapsed' => true)) ->add('enabled') ->add('createdAt') ->end() ->end(); ```
fix
+ added tab support on edit page * fixed CS issues on BaseGroupedMapper.php
Merge pull request #2337 from davidromani/master

Imporve catalan translation
continue implementation of tab support
Update SonataAdminBundle.bg.xliff

Add missing translations
Merge pull request #2343 from Warxcell/patch-2

Update SonataAdminBundle.bg.xliff
Revert "Update SonataAdminBundle.bg.xliff"
Merge pull request #2344 from sonata-project/revert-2343-patch-2

Revert "Update SonataAdminBundle.bg.xliff" - contains duplicate translation keys.
Improved ListMapper error handling.
Merge pull request #2345 from pulzarraider/listmapper_duplicate_exception_improved

Improved ListMapper error handling.
Refactored add_block.html.twig - fixed CS and bugs
Merge pull request #2346 from pulzarraider/add_block_fix

Refactored add_block.html.twig - fixed CS and bugs
Fixed wrong handling _per_page and _page datagrid parameters in php 5.3
Merge pull request #2348 from pulzarraider/per_page_fix

Fixed wrong handling with _per_page and _page datagrid parameters in php 5.3
Add tip about 'required' in sonata_type_collection

Document 'required' option behavior in sonata_type_collection
Merge pull request #2302 from caponica/fix_transformer_array_access_entity

Fixed problem with ModelToIdPropertyTransformer and ArrayAccess entities
Pass admin through to autocompleteItems callback:
~ modified HelperController::retrieveAutocompleteItemsAction() to pass $targetAdmin through to callback instead of $datagrid
~ updated documentation of the callback