filter	:	grocery_crud_list_item_class,
During items listing, send current row class and current row array

grocery_filter_row {
	type :	filtet
	desc 	:	filtre les lignes des entrées
}

grocery_callback_update	{
	type : action
	desc : callback before update
}

grocery_callback_insert	{
	type : action
	desc : callback before update
}

grocery_add_url {
	type : filter
	desc : change default add url
}

grocery_add_text {
	type : filter
	desc : change default add text
}

grocery_filter_actions {
	type : filter
	desc : filter custom grocery crud actions
}

grocery_filter_delete_button {
	type : filter
	desc : filter delete button
}

grocery_filter_edit_button {
	type : filter
	desc : filter edit button
	params : {
		string : button string,
		object	: row object
		string : button text
		string : button subject
	}
}

grocery_row_actions_output {
	type : filter
	desc : filter row dom at end
	params : {
		$row, $this->l('list_edit'), $subject
	}
}

grocery_registered_fields {
	type 	:	filter
	desc	:	filter registered fields
	params	:	$fields, an array with object {
		field_name	:	'',
		display_as	:	'',
		description	:	''
	}
}

grocery_edit_fields :  {
	type 	:	filter
	desc	:	return editable field for grocerycrud
	params	:	$fields, an array with object {
		field_name	:	'',
		display_as	:	'',
		description	:	''
	}
}

grocery_required_fields	:	{
	type	:	filter
	desc	:	return required field for form validation
	params 	:	array( 'FIELD_NAME', ... )
}

grocery_header_buttons : {
	type 	:	filter,
	desc 	:	let you add more button on table head 
	params 	:	[
		text 	:	'foo',
		url 	:	'http://bar.com'
	]
}
