add xml parsing bits.  untested, in progress
add libxmljs package dependency for xml parsing
parsing cas response xml

added a simple testing file, will delete later, but anyway, this is
how libxmljs works, using real cas responses

modified lib/cas_validate to use the sax parser.  The sax parser is an
event parser, so it is annoying but fine.  anyway, what I do is parse
the returned doc on checking a ticket, and check for success or
failure.  On success, I log the person in and stash the user inthe
session.  I will also add the cas attributes when we turn that back on
for testing.

on failure, I just do nothing other than log it in the logs

Then at the end of parsing the cas doc, I redirect to the original
url, with the ticket removed from the query.  This will prevent double
tripping the ticket handler.
fix the ticket hanging about past its welcome

remove search and remove query

seems to work okay in practice, but no test yet.
little trial program is properly parsing cas attributes
presentation
moving along
more work

sorted how to get prism highlighting (use language-javascript after
code fence ```)
make sure that when running test, you can see lots of diagnostics

if you want.  if so set env LOGLEVEL='debug'
uncomment commented tests
xml processing, seems complete, no tests
presentation is done.  saving to move around
edits right before the presentation

modified:   cas_validate_2.html
modified:   css/stack.css
presentation, done and presented

posted the pdf up to speakerdeck and linked to lanyrd site
dropped spoof firefox in test

pretending to be firefox is no longer necessary with CAS 2.5.2.  Not
sure about older versions, but all tests passed without it, so it
should not be in there.

Also minor edits to cas_validate, getting rid of console.log statements
in the xml parsing code
runtime tests of trying to get rid of ticket param in url.  failed

It doesn't seem to work when I try to remove the ticket from the URL.
Firefox at least resets the session and so you lose your login status,
resulting in an endless redirect loop to CAS
Merge branch 'feature/apereo_conf' of ssh://lysithia.its.uci.edu/home/james/repos/jem/cas_validate into feature/apereo_conf

Conflicts:
	lib/cas_validate.js
Merge branch 'feature/apereo_conf' into feature/xmlvalidate

The conference is over, so get back to working on xml validate branch proper
strip out determine service.  require option.service

throws if hte service is not set, for all but the logout handler.
Closes #11
starting modularization

broke out logger, sax parser

tests are passing