Added incident_manager.php

- When user clicks on incident id in the incident dashboard, they are
taken to incident_manager.php.
- Here, the information about the selected ticket is loaded into various
input boxes - the only input that is editable is the status.
- If the user updates the status, they must fill out the incident
narrative to submit changes successfully (functionality not yet
implemented).
- If the status is updated to closed, the user must also fill out an
incident resolution field in order to submit the change (functionality
not yet implemented).