A (slightly modified) patch from Yvan Cauchy for "Trigger for service to run upon subscription expiry" https://issues.apache.org/jira/browse/OFBIZ-5333

We are also proposing to add the following fields:

    ProductSubscriptionResource.gracePeriodOnExpiry
    ProductSubscriptionResource.gracePeriodOnExpiryUomId
    Subscription.gracePeriodOnExpiry
    Subscription.gracePeriodOnExpiryUomId

This will allow the runServiceOnSubscriptionExpiry to trigger the service in SubscriptionResource.serviceNameOnExpiry only after

nowTimeStamp >= Subscription.thruDate + Subscription.gracePeriodOnExpiry.

This provides flexibility in managing the triggering of the deprovisioning service, similar to the flexibility in automatic subscription extensions enabled by Subscription.canclAutmExtTime for runSubscriptionAutoReorders. 

jleroux: 
I replaced tabs by spaces
Will commit the change in serviceResult.ftl apart
Slightly reformatted SubscriptionServices.runServiceOnSubscriptionExpiry()
Slightly reformatted and added comment in services_subscription.xml for the 2 new services


git-svn-id: https://svn.apache.org/repos/asf/ofbiz/trunk@1597235 13f79535-47bb-0310-9956-ffa450edef68