Calc module changes: previewing and <formulaequationinput>

To see individual commits, see tag peterb/formula-preview/presquash

Named `FormulaEquationInput` (name up for debate)

- Based off ChemEqnIn
- Add FormulaEquationInput in inputtypes.py
- Add a call to a skeleton method for a preview

javascript:

- Queue up some MathJax
- Put some ordering on the AJAX requests: add a parameter when the request was started, when it returns check that it isn't outdated before displaying the preview
- Tests

Note: we moved the `jsinput` tests and DISABLED them, because they were causing the tests to fail.

- Create a method called `parse_algebra`. It takes a string of math and returns with a `pyparsing.ParseResults` object representing it.
- `evaluator` takes this tree and applies the old "parse actions" to it to get the same number as it used to.
- Change calc's API: `evaluator` to use `case_sensitive` rather than `cs`
- Add most of the capability for latex rendering

Failing JavaScript tests in Firefox

Fix manage.py to ouput the help of the django command if requested

Fix mysql indexing validity in migrations

Blapenta/site packages

Make CMS user view not show ErrorDescriptor courses

Feature/cdodge/convert to portable links on import and clone

Fix jumping to the top of the page on unit delete.

add a few debug messages to get localhost debug information. Also partition out the MongoDjangoToolbar configuration into a separate env config. This is because doing imports on large courses grinds localdev to a halt due to all the stack trace generation.

add another test. Seems like we never had an explicit test on an import into a new course-id. This fixes that

also support a link rewriting on course import and clone for the following format /courses/[org]/[course]/[run]/. We just need to substitute in the new course-id.

add ability to rewrite links on the old /courses/<org>/<course>/<run>/jump_to/i4x://&lt;org&gt;/&lt;course> .. intracourseware linking to the new portable /jump_to_id/<id> format

changing http:// to // on intro video urls

Upgrade diff-cover to newest version

Jonahstanley/fix courseteam tests

Fix enroll-multiple button

Feanil/master with release

make template string unicode

Add cronjob analytics to instructor dashbaord