[session] Ensure access to rql varmaker always mark the session as dirty
When one accesses the rql_varmaker, that's usually to use it. The pb was that when
the varmaker was already in page's data (which is stored as session data),
session storage such as redis won't see that the session data is dirty and has
to be stored back at the end of the request.
To fix this, systematically call set_page_data.
(grafted from 3432f0e2540d)
addressbook
basket
blog
book
calendar
comment
company
email
file
folder
i18ncontent
keyword
link
mailinglist
person
tag
timeseries
vcsfile