Research Article: The Extreme Light Infrastructure: Multi-disciplinary Science and Research Applications of Ultra-intense and Ultra-short Laser Pulses - Allen Weeks, Katalin Varjú, Ádám Börzsönyi, Dimitris Charalambidis, Subhendu Kahaly, Péter Dombi, Jakob Andreasson, Sergei Bulanov, Roman Hvězda, Daniele Margarone, Bedrich Rus, Gábor Szabó, Stefan Weber, Extreme Light Infrastructure (ELI)