Is Eid-e-Milad-ul-Nabi (P.B.U.H) allowed or prohibited?

Milad-ul-Nabi (P.B.U.H) is being celebrated in various parts of Muslim countries every year. 1. Is it proved from Quran and Sunnat-e-Rasool (P.B.U.H)? 2. Does Sahaba celebrated it? 3. If someone don't attends this. Should he be called a "Satan(Iblees)"?