Modified model packages of GrupoC-Model:

src/main/java/ ar.edu.unq.desapp...
> model.bean
	+Author
	+Book
	+Librarian
	+LoanBook
	+User
	+LoanConfiguration
> model.mailer
	+EmailService
	+NotificationSystem
> model.search
	+SearchBookSystem
> utils.builder (before in src/test/java)
	+BookBuilder
	+BuilderToTest
	+LibraryUserBuilder

src/test/java => change package name ar.edu.unq.desapp to ar.edu.unq.desapp.model