Prefix generated custom field names with taxonomy name

[dotherightthing]

		public function create_options( $term_id, $tt_id ) {

			$taxonomy_options = $this->get_options();

			foreach ( $taxonomy_options as $name => $attributes ) {

				if ( isset( $_POST[ $name ] ) && '' !== $_POST[ $name ] ) {
					$group = sanitize_title( $_POST[ $name ] );
					add_term_meta( $term_id, $name, $group, false );
				}
			}
		}

	$wpdtrt_tourdates_taxonomy = new WPDTRT_Tourdates_Taxonomy(
		array(
			'name'                      => 'wpdtrt_tourdates_taxonomy_tour',
			'plugin'                    => $wpdtrt_tourdates_plugin,
			'selected_instance_options' => array(),
			'taxonomy_options'          => array(
				'term_type'    => array(

term_type -> wpdtrt_tourdates_taxonomy_tour_term_type