Ensure atom.cmd --wait correctly waits in Windows cmd & powershell

resources/win/atom.cmd

@@ -22,30 +22,13 @@ FOR %%a IN (%*) DO (
   )
 )
 
-rem Getting the process ID in cmd of the current cmd process: http://superuser.com/questions/881789/identify-and-kill-batch-script-started-before
-set T=%TEMP%\atomCmdProcessId-%time::=%.tmp
-wmic process where (Name="WMIC.exe" AND CommandLine LIKE "%%%TIME%%%") get ParentProcessId /value | find "ParentProcessId" >%T%
-set /P A=<%T%
-set PID=%A:~16%
-del %T%
-
 IF "%EXPECT_OUTPUT%"=="YES" (
   SET ELECTRON_ENABLE_LOGGING=YES
   IF "%WAIT%"=="YES" (
-    "%~dp0\..\..\atom.exe" --pid=%PID% %*
-    rem If the wait flag is set, don't exit this process until Atom tells it to.
-    goto waitLoop
+    powershell -noexit "%~dp0\..\..\atom.exe" --pid=$pid %* ; wait-event
   ) ELSE (
     "%~dp0\..\..\atom.exe" %*
   )
 ) ELSE (
   "%~dp0\..\app\apm\bin\node.exe" "%~dp0\atom.js" %*
 )
-
-goto end
-
-:waitLoop
-  sleep 1
-  goto waitLoop
-
-:end