Cache find_admin
groups#show: first attempt to list members using jquery datatables.
first attempt to implement pdf address label export.
pdf export: changing font size to 10pt.
Warte-Icon durch Fußball ersetzen. Warum? 7:1 gegen Brasilien ;)
address labels pdf export: implementing sender line.
address labels pdf export: storing the sender address in session variable for convenience.
adress label pdf export: issue fixing.
address label pdf export: first attempt to cache the addresses.
address labels pdf export: second caching attempt: cache single address fields rather than whole lists.
refactoring the user#postal_address_with_name_surrounding into the class AddressLabel that can be cached.
caching address_label objects of the users in order to quickly create address label pdfs.

trello: https://trello.com/c/hBdNpedZ/644-adress-etiketten-verbessern
address label pdf export: make font smaller for longer address fields in order to have all addresses fit.
user: delete address_label cache when relevant information changes.
adding a 'minimal' layout for performace testing.

add the ?layout=minimal parameter to the url to use this.
groups#show: First steps to improve performance.

(1) Remove pagination.  (2) have former members not removed one by one
but using a subtraction.
groups#show: do not display deceased members ...

of a corporation within the corporation overview. This has confused
some people.
groups#show: caching users' titles.
groups#show: do not display the members count.

This causes problems at the moment, since all members, including all
members of the sub groups are counted.

Also, do not list members if there are too many.
groups#show: display `@members` count, not `@group.members`.

The old was removed in this commit:
https://github.com/fiedl/wingolfsplattform/commit/14ffed6cd829ce089efefe
af8eb796b400ef3b54

Trello: https://trello.com/c/RPlYvbcv/645-gruppen-seite-schneller-machen