D-Net

[Trunk | Notification Service]:
NotificationServiceCheckDeployController: [NEW] Controller added and
a. "hello()" method (@RequestMapping(value = {"", "/health_check"}, method = RequestMethod.GET)) which just prints and returns a greeting message.
b. "checkEverything()" method @RequestMapping(value = "/health_check/advanced", method = RequestMethod.GET) only accessible by PORTAL ADMINS which checks connection with db and prints properties.

[Trunk | Notificaton Service]:
1. NotificationConfiguration.java: [Bug fix] Commented @PropertySources (a library service should not set properties locally, but parent service is responsible for that).
2. NotificationController.java: For method "getAllNotifications()" (/all), set @PreAuthorize to PORTAL_ADMIN (instead of REGISTERED_USER) (used for testing)....

[Notificaton Service | Trunk]: Fix a bug user email on groups

[Notificaton Service | Trunk]: Create notification methods to create get and read notification