[ADD] core: vendor werkzeug 0.16's sessions.py

In Werkzeug 1.0, sessions support was moved out and into a separate
package (secure-cookies). Issue is distros are already starting to
update werkzeug to 1.0, without necessarily adding
secure-cookies (e.g. arch, debian experimental). Plus secure-cookies
has some changes e.g. different filename & al. So just vendor the
"continuity" version which is the last werkzeug before removal.

This commit copies the original file as-is so we can track eventual
changes if necessary.

0 files changed, 0 insertions, 0 deletions