Fix failing acceptance test

Adds a new Email link to the instructor dashboard for frontend interface to send
email to course members. Adds a feature flag ENABLE_INSTRUCTOR_EMAIL to toggle this.
Creates a new djangoapp bulk_email that handles this action by getting the recipient
list and batching the emails to different celery tasks to do the actual sending.
Requires lynx package to convert HTML email to plaintext. Handles SMTP errors by
retrying or falling through to the next email. Adds the option to opt out of course
specific emails in the user dashboard with an Email Settings link for each course.
Uses severable configurable settings with defaults. DEFAULT_BULK_FROM_EMAIL
specifies the from address for email. EMAILS_PER_TASK specifies the number of emails
each celery task takes on. EMAIL_HOST, EMAIL_PORT, EMAIL_HOST_USER,
EMAIL_HOST_PASSWORD, and EMAIL_USE_TLS for the SMTP email backend settings.

Co-authored-by: Akshay Jagadeesh <akjags@gmail.com>

Misc improvements to make lettuce testing a bit saner

Make the service-variant flag on manage.py longform only

Ihoover/feature flag auto auth

override .sr class from keeping tooltips hidden in sequence nav

Blank common and advanced problems now display an inline score of "0 points" upon creation

Embedded discussion component defaults to "Discussion"
Blank HTML page defaults to "Text"
Video component defaults to "Video"

These default names show up in tooltips.

Update diff-cover to latest version

remove test that csrf middleware is disabled (since we can't seem to reload middleware between tests)

move definitions from setuo into test method

Make cms.dev environment work with manage.py

change of defaults for rerandomize/showanswer

Add an XBlock student_view to XModule

Moved to xlint rather than setting to old default.

Warn user that the course behavior may change.

This just wraps XModule.get_html, and ignores javascript and css for
now.

[LMS-189]

Merge pull request #451 from edx/cale/add-a-manage.py-command-that-understands-the-extra-edx-options

Add a manage.py command that understands the extra edX options

Fix/adam/file upload

Conflicts:
	lms/djangoapps/courseware/tests/test_views.py

Hotfix 2013 07 23

It seems like self.tabs is getting set to an empty set [] now rather tha...

Conflicts:
	cms/templates/howitworks.html

Conflicts:
	lms/djangoapps/courseware/tests/test_views.py

add new test to assert that course creation will populate default tabs as expected. Also update factory to not override defaults on tabs array. Also simplfy self.tab test condition.

It seems like self.tabs is getting set to an empty set [] now rather than None. This causes the tab defaulting to not populate, leading to crashes in the LMS if someone makes a new course with additional tabs (e.g. static tabs or pdf-textbooks)

add a /jump_to_id/ shortcut for producing more durable links between cou...

Link section to course outline