Fixed bug: receiving own broadcasts.
Improved DiscoveryService implementing Observer pattern to notify of received announcements.
Implemented send functionality additional to the broadcast one.
Added serialVersionUID to ServiceAnnouncement.
Implemented HarmonicClient.

- Modified pom.xml to build both client and server;
- Updated ServiceAnnouncement to suit the needs of carrying more information;
- Implemented Server entity that represents a Server from the perspective of the Client and implements methods for connecting to it, requesting intervals and sending intervals;
- Implemented ConnectionFailedException to isolate the rest of the application from IO and network related exceptions.
Modified HarmonicClient so that it listens on any available port to servers' ServiceAnnouncement when finding servers.
Updated zeroconf to allow choice of port to send the announcement, maintaining compatibility using default port 44444.
[FIXED] Thread.start() missing.
[FIXED] Bug that caused Client to hang trying to connect to server that went down.
[FIXED] Bug that caused incorrect behavior of data transfer: was opening ObjectOutputStream more than once.
[FIXED] CalculationInterval type error.
First functional version. Server distributes same interval and prints results onto stdout.