[FIX] Event chat log download link
[IMP] Add room full name to http api
[MIN] always chown htdocs

avoids problems if htdocs is created by something else, e.g. puppet
[IMP] Removed unnecessary sphinx extensions

 * Causing security warnings in help pages
[IMP] Improved category date index script
Make worker name configurable
[FIX] RegForm: invalid radio radioitem id
[FIX] Paramater manager bug in abstract checking
[MIN] Removed unnecessary table tag
[FIX] StopIteration error on deleted fields

 * Causing issues on abstract accept
Do not show participation acc/rej form if sent

Once the user has accepted/refused the participation invitation
showing the form again resulted in a not very helpful error message.
Instead we now tell the user that he already accepted/rejected the
invitation.
Apply the same check on the reject-only form
Add missing i18n to participation "error" messages
[FIX] Registration HTTP API permissions
Make Config available in indico_shell by default
[FIX] Group clean groupmembership cache
[FIX] Electronic Agreement test with context
[IMP] RegForm: Add sorting criteria for checked in
[FIX] Typo masked by previous try..except

 * See previous commit
[FIX] Account for non-migrated fields