Termino de implementar la cola de transferencias.

 On branch issue_34
 Changes to be committed:

	modified:   database/ImageRepositoryDB.sql
	modified:   database/VMServerDB.sql
	modified:   database/imageRepository/imageRepositoryDB.py
	modified:   database/tests/VMServerDBTest.sql
	modified:   database/tests/vmServerDBTests.py
	modified:   database/vmServer/vmServerDB.py