##CmcGridFieldBulkUpdater
Allows changes to fields of multiple rows in a GridField that has GridFieldEditableColumns enabled
Nothing is saved. Items are updated in CMS view-only and not saved until 'Save & Publish' button clicked.
Requires silverstripe-gridfieldextensions https://github.com/silverstripe-australia/silverstripe-gridfieldextensions/blob/master/code/GridFieldTitleHeader.php
###Sample GridField config
//Bulk updater has to come after EditableColumns or Select added in first column
$groupGridField = new GridField(
'TrailGroupID'.$trailGroup->ID,
$trailGroup->getTitle(),
$trailGroup->Trails(),
GridFieldConfig::create()
->addComponent(new GridFieldToolbarHeader())
->addComponent(new GridFieldEditableColumns())
->addComponent(new GridFieldTitleHeader())
->addComponent(new CmcGridFieldBulkUpdater())
lang and select-all code pulled from GridFieldBulkEditingTools