Update way a subprocess is launched for Mac OS X.

Another applet mechanism has been developed for Python on Mac OS X and
trying to use the -c "__import__('run').main()" trick is just not working.

macosx_main.py is a new file which should be used as the startup file for
Mac OS X applet bundles. This startup file understands a -p option, which
when seen will start run.main(). When running as an applet, this seems like
the best approach.

Lib/idlelib/macosx_main.py

@@ -0,0 +1,46 @@
+"""IDLE.app
+
+Installation:
+  see the install_IDLE target in python/dist/src/Mac/OSX/Makefile
+  
+Usage: 
+
+1. Double clicking IDLE icon will open IDLE.
+2. Dropping file on IDLE icon will open that file in IDLE.
+3. Launch from command line with files with this command-line:
+
+     /Applications/Python/IDLE.app/Contents/MacOS/python file1 file2 file3
+
+"""
+
+# Add IDLE.app/Contents/Resources/idlelib to path.
+# __file__ refers to this file when it is used as a module, sys.argv[0]
+# refers to this file when it is used as a script (pythonw macosx_main.py)
+import sys
+
+from os.path import split, join, isdir
+try:
+    __file__
+except NameError:
+    __file__ = sys.argv[0]
+idlelib = join(split(__file__)[0], 'idlelib')
+if isdir(idlelib):
+  sys.path.append(idlelib)
+
+# Make sure True, False, bool() builtins exist.
+# - preserves 2.2 compatibility - 2.2.1 includes bool, 2.2 does not.
+# - important for Mac OS X because it ships python 2.2
+import boolcheck
+
+# see if we are being asked to execute the subprocess code
+if '-p' in sys.argv:
+    # run expects only the port number in sys.argv
+    sys.argv.remove('-p')
+
+    # this module will become the namepsace used by the interactive
+    # interpreter; remove all variables we have defined.
+    del sys, __file__, boolcheck, split, join
+    __import__('run').main()
+else:
+    # Load idlelib/idle.py which starts the application.
+    import idle