Update incidents one by one.

Use PUT methods for specific actions on the PagerDuty REST API.
Update incidents one by one. Reduce chance to fail. Allow incidents
to be unacknowled with the "reassign" method.
Update incidents by issue priorities.

Add "issuepriority" to the action configuration. Check issue
priority after issue status after they found by issue links.
Add required notes to the action configuration paramters on
on the README file. Update the default action configuration to
make is work by default.
Fix the JQL for updated issues.