Use PSR-3 error logging call. Remove unused import.

Signed-off-by: Max Fierke <max@maxfierke.com>
Add a Twig function for getting the default time resolution

Signed-off-by: Max Fierke <max@maxfierke.com>
Add unit tests for the SettingsExtension Twig extension.

Signed-off-by: Max Fierke <max@maxfierke.com>