By Michael Georgy CAIRO (Reuters) - Egyptian security forces fired bird shot and teargas to prevent supporters of deposed Islamist President Mohamed Mursi from marching on Sunday to the site of a protest camp that was destroyed two months ago, a Reuters witness said. The crowd of about 100 people were students from Al-Azhar University, the historic seat of Sunni Muslim learning. They threw rocks at riot police stationed outside the gates of the university, and police threw the stones back. ...