Merge step configuration without overriding non-empty values with empty ones

Conflicts:
	src/Oro/Bundle/BatchBundle/Job/Job.php
	src/Oro/Bundle/BatchBundle/Step/ItemStep.php
Add a method to synchronize the configuration of job steps
Remove default label and help options from step element configuration form
Make measure converter exception more accurate
Update attribute getters

Conflicts:
	src/Oro/Bundle/SearchBundle/Engine/AbstractMapper.php
Remove unused method
Revert "Remove unused method"

This reverts commit 1bf92efb0f971f8094ba1780bb6c7585b0d4adf4.
Revert "Revert "Remove unused method""

This reverts commit 130e0e0505920986c1d4c09ff13f7946c5d93bfe.
Made measure converter exception message more accurate
Merge maintenance/pim_beta4 batch updates into maintenance/pim_beta5