1. Revert subprocess environment clearing, will restart subprocess

instead.
2. Preserve the Idle client's listening socket for reuse with the
   fresh subprocess.
3. Remove some unused rpc code, comment out additional unused code.

Modified Files:
ScriptBinding.py rpc.py run.py

Lib/idlelib/ScriptBinding.py

@@ -147,8 +147,6 @@ class ScriptBinding:
         flist = self.editwin.flist
         shell = flist.open_shell()
         interp = shell.interp
-        # clear the subprocess environment before every Run/F5 invocation
-        interp.rpcclt.remotecall("exec", "clear_the_environment", (), {})
         # XXX Too often this discards arguments the user just set...
         interp.runcommand("""if 1:
             _filename = %s