initial commit of the lti outcomes service example tool

Change-Id: Ic7c26dd5a2fb8caa886cf423fae25c58be54a1ad
don't send 'undefined' for chart title

Change-Id: I3a899618d9d04d95d9f545d8ea71688b6050bbc2
add text_reader images

Change-Id: Ibd52211e454c82d7c93c0029c98af72837fb74e4
handle error on no window.parent access

Change-Id: I1e46278ef37434c097766e5e2fc1db6e2f6795c1
add xml config parser

I'm getting ready for supporting app delivery from multiple platforms,
and the easiest way to do that will be to start with some scripts.
In preparation for that, I'm adding support for jsonp callbacks that
can take an XML config and turn it into json that can then be used
to manually configure an app on-page. I'm envisioning modifying
the DOM of the Moodle settings page to show the app picker, then
populating the form correctly based on what the user selects.

test plan:
- make sure the tool can process xml
- make sure the tool does some lightweight validation
- make sure jsonp responses are working

Change-Id: I728270b0291a06affae9fc90f91433c1912ef5c0
update stored list of apps

Also fixed the parser to allow admins to manually set submitter
name and email, which is necessary for building the initial list
in the db from the json file.

Change-Id: If93bf2b2d6748ce0604d83fefd00820e203ab907
properly escape html entities in XML config

Before ampersands weren't being escaped properly, which was
causing errors in some xml responses.

test plan:
- add ampersands to launch_url and title
- make sure XML parsers don't choke and that the URL comes
  out the other end correctly

Change-Id: I444ec03d89549c1f1b14d2e2065e6d40b87faa53
add homework_submission support to app center

The next Canvas LTI extension allows homework submissions via
LTI launches. Add support for this in the app center configuration
and xml files.

Change-Id: Icec674c36313287ac140a27e29e53e8c10e2870c
add new logos

Change-Id: Ia58c93bc9c19b07303b9711c23bb429941242a0b
change 'lti apps' to 'edu apps'

Change-Id: I664436c8f9db37aedcd63007c2056f93b5a4689e
change talk to new twitter widget

Change-Id: I84b43b236689d3b7d590d809a2dd6a8f8b7441bc