Adding pit_plot.py

I'd appreciate it if has any comments on something I've been playing with _before_ is push it out in the tree. Basically, it's another way to visualize Q, D & C traces utilizing the xmgrace program. The work-flow is something like:

% blktrace...
% blkparse -d bp.bin ...
% btt -i bp.bin -P pit ...
% pit_plot.py XXXXpit.dat
% xmgrace XXXXpit.agr

A quickly thrown together document can be found at:

http://free.linux.hp.com/~adb/2008-11-11/pit_plot.pdf

The (crudely crafted) Python script is at:

http://free.linux.hp.com/~adb/2008-11-11/pit_plot.py

And the proposed patch would be at:

http://free.linux.hp.com/~adb/2008-11-11/0001-Added-pit_plot.py.patch

with the synopsis being:

From d05c0f3c9349cd3db31946fa049609c12333dee2 Mon Sep 17 00:00:00 2001
From: Alan D. Brunelle <[email protected]>
Date: Tue, 11 Nov 2008 17:03:37 -0500
Subject: [PATCH] Added pit_plot.py

Creates an xmgrace plot file from data generated by btt's -P option.

Refer to the documentation for more details.

---
 Makefile                    |    2 +-
 btt/doc/Makefile            |   21 +-
 btt/doc/buttons.eps         |  392 ++
 btt/doc/magnifier-final.eps | 6057 +++++++++++++++++++++++++++++++
 btt/doc/magnifier-post.eps  | 6224 +++++++++++++++++++++++++++++++
 btt/doc/magnifier-pre.eps   | 8468
+++++++++++++++++++++++++++++++++++++++++++
 btt/doc/ori-screen.eps      | 8368
++++++++++++++++++++++++++++++++++++++++++
 btt/doc/pit_plot.tex        |  205 ++
 btt/pit_plot.py             |  475 +++
 9 files changed, 30206 insertions(+), 6 deletions(-)