1. When a module is run from an EditorWindow, if its directory is not in

sys.path, prepend it.  This allows the module to import other modules
   in the same directory.  Do the same for a script run from the command
   line.
2. Tweak the IDLE usage message a bit more.

SF Bug 706860 (closed)
SF Patch 686254 (reject specific solution)
SF Patch 507327 (similar)

M PyShell.py
M ScriptBinding.py