add setting for turning off motivational features
mark some HTML elements as motivational features that can potentially be disabled
add ab_testing.css
hide knowledge map icons when we toggle off motivational features
set the real_password for student mixins
indent html by 4 spaces
check local_settings for the value of TURN_OFF_MOTIVATIONAL_FEATURES
add TODO-BLOCKER to move ab_testing.css to future ab_testing app
add assert to make sure we have Nalanda package activated
Merge branch '2167' of https://github.com/aronasorman/ka-lite into fixed_exercise_block
add assert to make sure we have Nalanda package activated
Merge branch '2167' of https://github.com/aronasorman/ka-lite into fixed_exercise_block

Conflicts:
	kalite/distributed/views.py
JS template for A/B testing, and make FIXED_BLOCK_EXERCISES changeable.