Añado la edición de una imagen existente al servidor de cluster.

 On branch issue_38
 Changes to be committed:

	modified:   clusterServer/networking/packets.py
	modified:   clusterServer/reactor/clusterServerReactor.py
	modified:   database/ClusterServerDB.sql
	modified:   database/clusterServer/clusterServerDB.py
	modified:   testing/clusterServerTester.py
	modified:   virtualMachineServer/threads/compressionThread.py
	modified:   virtualMachineServer/threads/fileTransferThread.py