Register SparkPost settings with CiviCRM
Created by: universalhandle
This PR registers the SparkPost settings with CiviCRM.
This provides the necessary metadata for the setting to appear in the API Explorer, for instance. It also allows for setting the apiKey in civicrm.settings.php, a la $civicrm_setting['com.cividesk.email.sparkpost']['apiKey'] = 'bananas';
. I don't believe the value can be set via the API without this change.
To facilitate this, I needed to upgrade the civix templates, which was quite old.