[server] implement dynamic database pooler
Opening too much database connection has a cost at startup and also PostgreSQL
as a maximum number of connection (100 by default).
This get worse when starting multiple wsgi processes, since each process has
its own database pool.
Instead of opening `connections-pool-size` connections to the database at
startup, just open one and open more only when needed.
CSS Coding Standards
--------------------
(Draft, to be continued)
:Naming: camelCase
Indentation rules
~~~~~~~~~~~~~~~~~
- 2 spaces before properties
- no space before ":", one space after
- only one space between values of the same property
Documentation
~~~~~~~~~~~~~
Please keep rules semantically linked grouped together, with a comment about
what they are for.
Recommendation
~~~~~~~~~~~~~~
- Try to use existing classes rather than introduce new ones
- Keep things as simple as possible while in the framework
- Think about later customization by application
- Avoid introducing a new CSS file for a few lines of CSS, at least while the
framework doesn't include packing functionalities