Commit deba32cad9 upgraded the Servlet API mocks to Servlet 3.0;
however, not all of the Javadoc was updated accordingly.
This commit updates the remaining Javadoc with regard to Servlet 3.0 as
the baseline for mocks in the spring-test module.
In addition, this commit syncs up the mocks used for internal testing in
the spring-web module with the most current versions from spring-test.
Issue: SPR-11049