TCK coverage missing for attribute elements of cookie-config introduced since web-common_6_0.xsd

[pferraro]

The Servlet TCK currently lacks test coverage for the attribute elements of cookie-config that were added to web-common_6_0.xsd as part of 95d1047#diff-be47399ec28cd54bcd249ec1658f715fee37a90bf80612609fbebfa78fe5d575

[markt-asf]

Having looked at the various SessionCookieConfig tests in the TCK, none of them test the cookie-config element in web.xml.