function columnsParser (columns, currentList) {
	if (!currentList) {
		throw new Error('No currentList selected');
	}
	if (!columns || columns.length === 0) {
		return currentList.expandColumns(currentList.defaultColumns);
	}
	return currentList.expandColumns(columns);
}
Returns an array of expanded columns object, given a list of columns and currentList object.

@param { String } columns, a string representation of a list of columns.
@param { Object } the current instantiation of the List prototype used for the <List/> scene
@return { Array } of { Objects } as an expanded representation of the column values passed in.