Manage Events : Allow users who do not have administer CiviCRM permission to create and manage events and import participants

We have gotten feedback from the community that creating and updating events is a frequent task that shouldn't be restricted to users with "administer CiviCRM" permission. Modify the access control to allow users w/ "access CiviEvent" permission to do this task. Modify CiviEvent Dashboard to expose the "New Event" and "Manage Event" action links w/o requiring "administer CiviCRM" permission.

Also modify permissions on "Import Participants" to require "access CiviEvent" and "edit event participant" permissions (rather than "administer CiviCRM").