Fix multi-template rendering in WPJinjaMixin
Pass along kwargs in WPCategoryBase
Add conference-header template hook
Remove unused var from WHTMLHeader

It just caused errors during development when deleting pyc files without
restarting the dev server...
Remove nonsense from legend
Rename page-header hook to html-head

Because that's what it does: insert stuff in the <head>. it is not
related to the "header" of the page..
Add page-header template hook
Remove the old search plugins
Remove the old outlook plugin
Add signal to inject timetable buttons
Remove Importer plugin contributions
Remove unused extension points
Remove htdocs from importer plugin
Change how custom links are built in timetable
Handle dict with unicode strings
Remove unused services
Remove all importer-related code from core