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/run.py

@@ -1,7 +1,6 @@
 import sys
 import time
 import socket
-import __main__
 import rpc
 
 def main():
@@ -56,18 +55,11 @@ class Executive:
 
     def __init__(self, rpchandler):
         self.rpchandler = rpchandler
-        self.base_env_keys = __main__.__dict__.keys()
+        import __main__
+        self.locals = __main__.__dict__
 
     def runcode(self, code):
-       exec code in __main__.__dict__
-        
-    def clear_the_environment(self):
-        global __main__
-        env = __main__.__dict__
-        for key in env.keys():
-            if key not in self.base_env_keys:
-                del env[key]
-        env['__doc__'] = None
+        exec code in self.locals
 
     def start_the_debugger(self, gui_adap_oid):
         import RemoteDebugger