By SARA VANDEN BERGE   The cities of Stephenville and Dublin are gearing up to host their annual community-wide Easter egg hunts.   Both events are free. Stephenville will host the “Megga Hunt” from 10 a.m.-noon on Saturday, April 4, at Stephenville City Park.   The annual event is co-sponsored by the city and Timber Ridge Church.   Along with the hunt, there will be games, activities and bounce houses. DUBLIN’S EGGSTRAVAGANZA   Dublin’s 5th annual EGGStravaganza will take pl