Colorize "as" after "import" / use DEBUG instead of __debug__

standard usage is now from IdleConf import idleconf

replace : with = in config.txt

idle.py:
    Load the config files before anything else happens
    XXX Need to define standard way to get files relative to the
       IDLE install dir

PyShell.py:
ColorDelegator.py:
    Get color defns out of IdleConf instead of IdlePrefs

EditorWindow.py:
    Replace hard-coded font & window size with config options
    Get extension names via IdleConf.getextensions

extend.py:
   Obsolete.  Extensions defined in config file.

ParenMatch.py:
   Use config file for extension options.
   Revise comment about parser requirements.
   Simplify logic on find returning None.

Ho ho ho -- that's trickier than it sounded!  The colorizer is working with
"line.col" strings instead of Text marks, and the absolute coordinates of
the point of interest can change across the self.update call (voice of
baffled experience, when two quick backspaces no longer fooled it, but a
backspace followed by a quick ENTER did <wink>).

Anyway, the attached appears to do the trick.  CPU usage goes way up when
typing quickly into a long triple-quoted string, but the latency is fine for
me (a relatively fast typist on a relatively slow machine).  Most of the
changes here are left over from reducing the # of vrbl names to help me
reason about the logic better; I hope the code is a *little* easier to

dramatically (up to 15 times he claims).  Works by reading more than
one line at a time, up to 100-line chunks (starting with one line and
then doubling up to the limit).  On a typical machine (e.g. Tim's
P5-166) this doesn't reduce interactive responsiveness in a noticeable
way.

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.

priority over text colorization (which on Windows is almost the
same color as the selection background).

Define a tag and color for breakpoints ("BREAK").

Features: text editor with syntax coloring and undo;
subclassed into interactive Python shell which adds history.