mshtml COM interface returns None when value is empty: we need to correct this to return empty string
mshtml COM interface returns None when value is empty: we need to correct this to return empty string

git-svn-id: 6db40d0534cac73ba019dccfebee869402ecad0c@2377 7a2bd370-bda8-463c-979e-2900ccfb811e

certik/pyjamas,certik/pyjamas,certik/pyjamas,certik/pyjamas