PRPhotos.comHappy Birthday to Eric Clapton, who turns 77 today (March 30th)!!! Since his mid-’60s stint in the Yardbirds, through John Mayall’s Bluesbreakers, Cream, Blind Faith, Derek & The Dominos, and his solo career, Clapton — who was affectionately dubbed “Slowhand” by his fans — has come to personify the best in blues-rock guitar. Clapton holds…