Checking in IDLE 0.2.

Much has changed -- too much, in fact, to write down.
The big news is that there's a standard way to write IDLE extensions;
see extend.txt.  Some sample extensions have been provided, and
some existing code has been converted to extensions.  Probably the
biggest new user feature is a new search dialog with more options,
search and replace, and even search in files (grep).

This is exactly as downloaded from my laptop after returning
from the holidays -- it hasn't even been tested on Unix yet.

Tools/idle/extend.py

@@ -0,0 +1,9 @@
+# IDLE extensions to be loaded by default (see extend.txt).
+# Edit this file to configure your set of IDLE extensions.
+
+standard = [
+    "SearchBinding",
+    "AutoIndent",
+    "AutoExpand",
+    "ZoomHeight",
+]