String unescaping modifies the buffer used for the cookie, and will corrupt the original cookie header
[visible when displaying them using getHeader]. Experiment with an option to preserve them. I don't think
this should be the default, as it is almost never useful, and can be a bit wasteful.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1448679 13f79535-47bb-0310-9956-ffa450edef68