Compatibility extension and new features

This release is now compatible with Jira from version 7 to 8.x.

New features and fix:

• Fixes an error when trying to notify a reporter who has no email (or who is inactive or absent) :
  • A log line is added to jira log with issue key and reason why reporter is not notified
  • An email is sent to the issue's assignee so that he or she knows no notification is sent to reporter
• Now the evaluations screen shows the number of answered surveys and the total number of surveys
• Two JQL functions added to get the list of issues with an answered survey and those with an unanswered survey.