followup, actually only validate if the subscription isn't already active, regardless of whether its new or not

followup, only implement this rule for new subscriptions

Issue #1789496 by bjlewis2: Added When subscription is manually set to 'Grace Period", "Expired" or "Cancelled" set end date to "now".

just because

improved add/remove role logic

Issue #1789322 by alexweber: Fixed Allow admins to create subscriptions on behalf of users even if they don't have 'create" permission.

prefixed rules actions with "subs_rules" to make it clearer which functions are rules action callbacks and which are Drupal core actions

Implemented actions for all subscription operations

refactored create subscription block to use new permissions

added extra "create" and "delete" permissions per subscription type

removed general access check in create subscription block

cleanup code