Create the DbAdapterFactory to instanciate db adapters, add resources.ini to configure resources, change
the authentication Manager to fall back to backends with lower priority in case
of errors, update the current UserBackends to the changed environment. Also
adjust the documentation and existing unit tests.
resolves#4503
Add an ini writer that respects the file structure and the comments that may be
already present in the config file. Move Application/Config.php into
Config/Config.php.
refs #4352
Fix installation instructions for postgresql, the user table is now
'account', as user is a keyword in some rdbms, now catching exceptions
and returning auth failed while logging errors
refs #3769
Add functionality to check if a certain database type like psql or mysql is
available and skip the tests accordingly.
Add documentation for backend authentication.
refs #3769
