Moves CSV submission download to celery task

Emails the CSV as attachement upon task completion
(closes #1997)
change file attachment to s3 download link due to size issues
put file close in finally block
Merge pull request #2354 from Stanford-Online/jbau-csv-report-celery

Moves CSV submission download to celery task
Merge pull request #2381 from Stanford-Online/jbau-random-psets

Jbau random psets
changed output of facebook and g+ widget and removed hard-coded # from twitter one
Create generic manage.py tools infrastructure

* Move certificates/ toplevel under tools/
* Create tools/aws directory
* create aws_getinfo target, which gathers information about the hosts
  in our host groups for use in system startup and configuration
Check in candy components for chat support

* Add candy chat system components for serving from static/
* Proptotype candy component delivery to /course/handle/chat
* Introduce JABBER_DOMAIN variable and document it in
  database_example.py
Initial chat on course home page demo prep

* Embed candy page in iframe on course home page above announcements
* Customize Candy CSS to fit into the look and feel of class2go somewhat
  more
Chef configuration to install ejabberd

* Chef cookbooks for installing ejabberd and doing simple configuration
Fixes to ejabberd recipes and courses/views

* Rewrite of ejabberd installation recipes to avoid wiping mnesia tables
  unless this is a first-time install.
* Also, recipe uses octal mode notation only (strings removed)
* Also, template for ejabberd defaults file is actually a template
* Fix in courses/views to use hasattr instead of getattr
Merge branch 'master' of https://github.com/Stanford-Online/class2go into giulio-share-results
Merge pull request #2389 from Stanford-Online/giulio-share-results

Changed output of sharing widgets (fixes #2386 and fixes #2387)
Merge pull request #2391 from Stanford-Online/jbau-random-psets

Fixes xml metadata confirmation message.
Making mnesia table destruction safer
Merge pull request #2384 from Stanford-Online/jrbl-tps_reports_prototype_2

Jrbl tps reports prototype 2
default null for examrecordscore
Merge pull request #2395 from Stanford-Online/jbau-alter-migration-8

default null for examrecordscore
tweet buttons get correct total score for randomize