Lab: Web Technology

Covers
* HTTP (httplib, requests)
* XML (DOM, SAX or ElementTree)
* WSGI (wsgiref)
add Web Technology lab to Volume 3
add TCP/IP section

Outline rest of the lab.
explain JSON

Explain what JSON is and basic reading and dumping.
explain XML

Begin section on XML.  Explain the difference between DOM and SAX.
more xml content
Merged the first two MPI labs bc they are short
And took it out of tex doc
Changed the directories
Redid line breaks in hysteresis lab.
Simplified code in hysteresis lab.
Added some hints and updated some formatting.
Fixed some typos found by students.
initial commit of chat client/server

The grand culmination project of the lab.
Chat over HTTP using JSON.
introduce concept of serialization.
expand ElementTree explanations

give examples for parse and iterparse.
Added a first draft of the lab on the finite volume method by Jared Whitehead. Also revised the  lab on wave phenomena.
Merge branch 'develop' into finite_volume

Merge finite_volume into develop branch
Modified finitevolume.tex
remove IPython Notebook recommendation + fixes

We should not be recommending the IPython notebook as the standard
interface.  While we do suggest that they use IPython, we should let
them choose their preferred environment.

Also, the IPython notebook does not work well with automated grading.

Made other various fixes.