chronos migration wip

- [ ] Need to review `traceAsyncErrors`
- [ ] Handle new `except`s

asyncprocmonitor.nim

@@ -1,12 +1,15 @@
 # Monitor a client process and shutdown the current process, if the client
 # process is found to be dead
 
-import os, asyncdispatch
+import os, chronos, utils
 
 when defined(posix):
   import posix_utils
   import posix
 
+type Callback* = proc() {.closure, gcsafe, raises: [].}
+
+
 when defined(windows):
   import winlean
 
@@ -19,14 +22,12 @@ when defined(posix):
 
     var processExitCallbackCalled = false
 
-    proc checkProcCallback(fd: AsyncFD): bool =
+    proc checkProcCallback(arg: pointer) =
       if not processExitCallbackCalled:
         try:
           sendSignal(Pid(pid), 0)
         except:
           processExitCallbackCalled = true
-          result = cb(fd)
-      else:
-        result = true
-
-    addTimer(1000, false, checkProcCallback)
+
+
+    addTimer(1000.int64, checkProcCallback)