Put into a large bowl, dry yeast, sugar, salt and 1 cup flour; mix. Add warm water and 3 eggs and mix with mixer until smooth. Mix in margarine and the rest of the flour to make soft dough.
On floured board, knead dough for 5 minutes. Place in bowl and let rise for 45 minutes. Punch down; chill dough for 15 minutes. While dough is raising mix together cream cheese, bacon and onion for filling.
Roll out 1/2 of dough in to 2 10in. circles. Spread with 1/4 (each) of filling. Cut into 6 wedges. Ross into crescents. Place on baking sheet. Repeat with other dough. Let rise for 45 mins.
Brush with egg/milk mixture and then bake at 425 degrees for 8-10 minutes.