Overview
---------
This pull request makes this XBlock extensible for
adding parameters to the LTI provider in addition
to the existing ones.

Why
---
A customer needs `team` and `cohort` informaiton
to be passed through the LTI channel to simplify
integration with their LTI provider. At the same
time we'd rather not fork the XBlock, so an
Open-Closed model is needed.

More Detailed Documentation
---------------------------
I've added a couple of sections to `README.rst`
to document specifying design and
configuration steps of the new LTI parameter
processors. Please check it out for more
information about the changes that this pull
request introduces.

Example Usage
-------------
I've written a package that we'll need to use for
our customer to pass some personal user
information in addition to the cohort and team
info: https://github.com/appsembler/tahoe-lti/pull/1

Omar Al-Ithawi @ Appsembler

Add context_label and context_title to LTI POST parameters; Add required requirements; add some docker devstack instructions;

Release new version for #31.

updated readme

fixed link

better fix for link

Updating code to look at UserProfile.language_proficiencies; updating tests; iterating version to 1.0.8

asadiqbal08: Updated branch as per suggestions
asadiqbal08: Addressed PR feedback
mattdrayer: Rebased branch, addressed merge conflict

Use django.utils.timezone.now() when determining if the due date of a component has passed to avoid tz-aware/naive datetime comparison bug

Toggle aria-hidden attribute on modal window open/close; Set title attribute on iframe to display name of component; Remove aria-labelledby attribute from modal body; Make modal overlay id attribute unique'