Fix max-age setting

 * It would not work for cookies set to expire tomorrow or later, since
setting the time in a BDateTime does not overflow to the date.
 * The BDateTime API could be improved to make this look nicer.
BUrl: parse URLs using a regular expression.

 * RFC3986 provides the regexp to parse URIs properly
 * Code is simpler and safer
 * Avoids an infinite loop when trying to parse some data: URIs
BNetworkCookie: Allow cookies without a path

 * They will be valid for the whole domain
 * login.live.com cookie test now works