RPC tests: create initial chain with specific timestamps

Use setmocktime to create the initial block chain with
10-minute-apart-blocks starting 1 Jan 2014.

qa/rpc-tests/util.py

@@ -103,11 +103,16 @@ def initialize_chain(test_dir):
 
         # Create a 200-block-long chain; each of the 4 nodes
         # gets 25 mature blocks and 25 immature.
-        for i in range(4):
-            rpcs[i].setgenerate(True, 25)
-            sync_blocks(rpcs)
-        for i in range(4):
-            rpcs[i].setgenerate(True, 25)
+        # blocks are created with timestamps 10 minutes apart, starting
+        # at 1 Jan 2014
+        block_time = 1388534400
+        for i in range(2):
+            for peer in range(4):
+                for j in range(25):
+                    set_node_times(rpcs, block_time)
+                    rpcs[peer].setgenerate(True, 1)
+                    block_time += 10*60
+                # Must sync before next peer starts generating blocks
                 sync_blocks(rpcs)
 
         # Shut them down, and clean up cache directories:
@@ -179,10 +184,14 @@ def stop_node(node, i):
     del bitcoind_processes[i]
 
 def stop_nodes(nodes):
-    for i in range(len(nodes)):
-        nodes[i].stop()
+    for node in nodes:
+        node.stop()
     del nodes[:] # Emptying array closes connections as a side effect
 
+def set_node_times(nodes, t):
+    for node in nodes:
+        node.setmocktime(t)
+
 def wait_bitcoinds():
     # Wait for all bitcoinds to cleanly exit
     for bitcoind in bitcoind_processes.values():