Merge tag 'sparks-1.18.2' into develop

1.18.2
Coffeescript enhancements, JS cleanups.
MongoDB tasks additions.
Propagate the django settings module ENV variable to `pip install …` commands, else some fails (yes, you fool, `django-mongodb-engine`!!). Refactor one more SPARKS_*.
disable the mongo -dev package, it doesn't exist in 10gen APT repository…
bump version in setup.py
Merge branch 'release/1.19'