Saving up new images (mockups)

	new file:   img/blackbox.jpg
	modified:   propuesta_seminario_1/presentacion/presentacion.tex
	modified:   src/soa_p2p.tex
	modified:   src/soa_p2p_user_identification.tex
	modified:   src/system.tex
	modified:   thesis.tex
	new file:   ../Growing-Power-Hungry-Internet.jpg
	new file:   ../img/login_protocol_mockup.png
	new file:   ../img/registration_protocol_mockup.png
	new file:   ../img/session_creation_protocol_mockup.png