Delete specified folder.
			Pass folder_etag to avoid race conditions (raises error 412).
			recursive keyword does just what it says on the tin.

def delete_folder(self, folder_id, folder_etag=None, recursive=None):
		'''Delete specified folder.
			Pass folder_etag to avoid race conditions (raises error 412).
			recursive keyword does just what it says on the tin.'''
		return self( join('folders', folder_id),
			dict(recursive=recursive), method='delete',
			headers={'If-Match': folder_etag} if folder_etag else dict() )