Meeting pages look funny

[ThiefMaster]

{% set previous_date = date %} at the end of a loop to check whether the value changed since the last iteration only worked because of a jinja bug (cross-loop sets were never supposed to work), which has been fixed in Jinja 2.9.

There are currently various workarounds that are more or less ugly (mutable objects with the do extension, or the groupby filter), but possibly there will be a clean solution to access the previous loop item in Jinja until 1.9.10 is ready for production.

Related jinja issue: pallets/jinja#641

[OmeGak]

A-ma-zing.

[ThiefMaster]

Just to keep track of another place where legacy jinja scoping is used: indico/modules/events/timetable/templates/display/administrative/_session_block.html

this one could make use of need the namespace idea suggested in pallets/jinja#641 (or abuse a mutable object for now)

[ThiefMaster]

This change should be reverted and replaced with one using the namespace object once we use a Jinja version containing pallets/jinja#684

[ThiefMaster]

c509c68 should also be updated once Jinja has been updated. In case the commit hash is invalid due to a rebase by then, search for templates containing {% set __ =