filters frontend improvements
Merge pull request #2458 from juherpin/master

filters frontend improvements
 style improvements for treeview
Merge pull request #2464 from juherpin/ui-fix

Style improvements for treeview
Added missing slovak translations
Added missing czech translations
also log previous exception message when available
Updated stylesheets and javascripts configuration
Removed old unused default configuration option parent:text from sonata_type_model_list, refs #2455
Merge remote-tracking branch 'origin/master'