Added line for 1.0
Added SESSION_REFRESH_EACH_REQUEST config option.

This also changes how sessions are being refreshed.  With the new
behavior set-cookie is only emitted if the session is modified or if the
session is permanent.  Permanent sessions can be set to not refresh
automatically through the SESSION_REFRESH_EACH_REQUEST config key.

This fixes #798.
Merge branch 'master' of github.com:mitsuhiko/flask