added comment about padding
added comment about padding

jlmucb/cloudproxy,jethrogb/cloudproxy,tmroeder/cloudproxy,jlmucb/cloudproxy,kevinawalsh/cloudproxy,jlmucb/cloudproxy,jethrogb/cloudproxy,jethrogb/cloudproxy,tmroeder/cloudproxy,jlmucb/cloudproxy,jethrogb/cloudproxy,kevinawalsh/cloudproxy,tmroeder/cloudproxy,tmroeder/cloudproxy,jlmucb/cloudproxy,jethrogb/cloudproxy,tmroeder/cloudproxy