Tim Peters: Taught it more "real Python" rules without slowing it

appreciably.  Triple-quoted strings no longer confuse it, nor nested
classes or defs, nor comments starting in column 1.  Chews thru
Tkinter.py in < 3 seconds for me; doctest.py no longer confuses it; no
longer missing methods in PyShell.py; etc.  Also captures defs
starting in column 1 now, but ignores them; an interface should be
added so that IDLE's class browser can show the top-level functions
too.