Implemented 'await connect' fully. Fixed a buffering and 'reqReg' bug.

* reqReq did not reset lastReq to reqNil, this caused problems in the
new tasyncitermacro test. (await accept stopped accepting requests after
some arbitrary amount have been accepted).
* Rewritten and moved tasyncitermacro to tests/run/ so that the tester
actually tests whether it works at runtime.
* tasynciterraw is now a copy of tasyncitermacro after macro expansion.
It will be used as a control test, useful if the macro starts generating
incorrect code.

tests/run/tasyncitermacro.nim

@@ -0,0 +1,78 @@
+discard """
+  file: "tasyncitermacro.nim"
+  cmd: "nimrod cc --hints:on $# $#"
+  output: "10000"
+"""
+import sockets, asyncio, strutils
+
+var globalCount = 0
+
+proc sendCount3(client: PAsyncSocket, count: int) {.async.} =
+  await send(client, $count & "\c\L")
+
+proc sendCount2(client: PAsyncSocket, count: int) {.async.} =
+  await sendCount3(client, count)
+
+proc sendCount(client: PAsyncSocket, count: int) {.async.} =
+  # Testing multiple levels of custom await calls. Shouldn't have much of a
+  # performance impact.
+  await sendCount2(client, count)
+
+proc processRequest(client: PAsyncSocket, paramTest: string, closeSock: bool = true) {.async.} =
+  doAssert paramTest == "foobarbaz"
+  assert client != nil
+  var count = 0
+  while true:
+    let line = await(readLine(client))
+    if line == "end": break
+    doAssert line.startswith("Message")
+    doAssert line == "Message" & $count
+    count.inc
+  
+  await sendCount(client, count)
+  
+  doAssert closeSock # Testing default params here. We won't be changing it.
+  if closeSock:
+    client.close()
+
+proc startServer() {.async.} =
+  var sock = AsyncSocket()
+  #sock.setReuseAddr()
+  
+  # The following may block, but I don't think it does.
+  sock.bindAddr(TPort(10235))
+  sock.listen()
+  
+  # Accept loop
+  while true:
+    let client: PAsyncSocket = await(accept(sock))
+    assert client != nil
+    
+    reg processRequest(client, "foobarbaz")
+
+proc spawnClient() {.async.} =
+  var client = AsyncSocket()
+  await connect(client, "localhost", TPort(10235))
+  
+  for i in 0 .. 99:
+    await send(client, "Message" & $i & "\c\L")
+  await send(client, "end\c\L")
+  
+  let line = await(readLine(client))
+  doAssert line == "100"
+  globalCount.inc(100)
+  client.close()
+
+proc spawnClients() {.async.} =
+  for i in 0 .. 99:
+    reg spawnClient()
+  
+var disp = newDispatcher(false)
+disp.register(startServer, nil)
+disp.register(spawnClients, nil)
+while true:
+  discard disp.poll()
+
+  if globalCount == 100*100:
+    echo(globalCount)
+    quit(QuitSuccess)