Improvements

Add support for admin-only designer placeholders. Such placeholders can be provided by custom plugins and only be used in the designer by Indico admins (#3210)
Sort contribution types alphabetically
Add folding indicators when printing foldable badges (#3216)

Bugfixes

Fix LaTeX rendering issue when consecutive lines starting with [ were present (#3203)
Do not allow managers to retrieve tickets for registrants for whom ticket access is blocked by a plugin (#3208)
Log a warning instead of an exception if the Indico version check fails (#3209)
Wrap long lines in event log entries instead of truncating them
Properly show message about empty agenda in reminders that have "Include agenda" enabled but an empty timetable
Fix overly long contribution type names pushing edit/delete buttons outside the visible area (#3215)
Only apply plugin-imposed ticket download restrictions for tickets, not for normal badges.
Fix switching between badge sides in IE11 (#3214)
Do not show poster templates as possible backsides for badges
Convert alpha-channel transparency to white in PDF backgrounds
Make number inputs big enough to show 5 digits in chrome
Sort chairperson list on lecture pages
Remove whitespace before commas in speaker lists
Hide author UI for subcontribution speakers (#3222)