Allow full project delete.

Issue Summary

When a project is deleted in JIRA, various configurations as well as users remain in it hence achieving a full clean delete is difficult.

For example, if I restore a backup but require just one project, if I delete all the other projects, settings such as permission scheme, configuration scheme, Workflows and users are still left in the system.

The feature we would like implemented would be able to delete all of these when the project is deleted.

Suggestion:
As most schemes can be shared, a notification should be shown when user attempts to delete a project that has such a shared scheme and the user would be allowed to confirm this.
If they confirm it, revert all such settings back to the default schemes for them.