I made the suggested code change to check if the "expires" parameter is null before calling the
getTime method on it.  If it is null, we pass 0 to setCookieImpl, effectively creating a session 
cookie instead.

Patch by: jlabanca
Review by: jgw
Issue: 1152, 658



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@1199 8db76d5a-ed1c-0410-87a9-c151d255dfc7