Mix chicken, cream cheese, chives, milk and salt in a medium bowl (mixing with hands works best) to make filling, and store in a 1 litre freezer bag. Put crouton crumbs in another 1 litre bag, attach it to bag of chicken filling, and freeze them. Refrigerate crescent rolls. To prepare for serving, thaw chicken mixture. Unroll crescent rolls. Each tube will contain 4 rectanngles of dough with a diagonal perforation. Press dough along each perforation so the rectangle halves will not separate. Place about quarter cup of chicken mixture into the center of each rectangle. Fold dough over the filling, and pinch the edges to seal tightly. Dip each packet in melted margarine, and coat with crouton crumbs. Place packets on a baking sheet. Bake in a preheated 350 oven for 20 minutes or until golden brown. Pakcets are good either hot or cold. Makes 8 packets.