reorganize examples into folder

contracts/examples/GoodPullPayments.sol

@@ -0,0 +1,24 @@
+contract GoodPullPayments {
+  address highestBidder;
+  uint highestBid;
+  mapping(address => uint) refunds;
+
+  function bid() external {
+    if (msg.value < highestBid) throw;
+
+    if (highestBidder != 0) {
+      refunds[highestBidder] += highestBid;
+    }
+
+    highestBidder = msg.sender;
+    highestBid = msg.value;
+  }
+
+  function withdrawBid() external {
+    uint refund = refunds[msg.sender];
+    refunds[msg.sender] = 0;
+    if (!msg.sender.send(refund)) {
+      refunds[msg.sender] = refund;
+    }
+  }
+}