make export a bit more resilient. If there's a piece of metadata that we can't serialize - i.e. someone wrote a new bool attribute and didn't put it in the type mapping table - then we log the exception and continue.

Fix/will/merge jnater unittests

Hotfix/jkarni/folditscore

Fix max_attempts=''

That's what studio defaults to, and recent changes made it break.
Added a few tests to make sure it doesn't happen again.

remove links to missing image files.  We can add them if needed later.

Added documentation for drag and drop - targets on draggables feature.

add textbook and pdf textbook documentation

Feature/jkarni/genex

Update correctmap to handle partially correct answers, and

fix annotation tests so that they use the new test_system functionality

Enable Django debug toolbar on Studio (including Mongo panel).

Refactor Chemical Equation Preview

Feature/abarrett/annotatable xmodule DO NOT MERGE

Give InputTypes the ability to handle their own AJAX

Use readonly attribute instead of disabled. Disabled text fields are not...

#225

Update tests to reflect new behavior.

to capa_problem