[server] use a LifoQueue in _CnxSetPool
In postgresql, some cache is attached to the connection. Using a LifoQueue
(last-in, first-out) makes a few connections to get the most load which give
best performance.
Add some entities
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As manager, you can access to entity creation forms by using the `site management`_ page.
.. _`site management`: ../manage
As regular user, the index page or the action box may propose some links to create entities according to the context.