Case importer rewrite

# Case importer rewrite

This pull request is for the overhaul of the outdated and ugly case importer tool.

## Goals:

### Allow creation of new cases

The main goal was to update the case importer to be able to create new cases as it could previously only update existing records. An option is now present to enable this.

![screen shot 2013-05-23 at 1 52 46 pm](https://f.cloud.github.com/assets/152134/556143/a25a8004-c3d1-11e2-9a48-817a359028df.png)

### More granular update tracking

Any case updated by the importer had a history record created that showed every field as being modified. The importer now properly creates an XML submission that only updates the fields selected to be modified by the importer.

### Fix various bugs

The existing code is old and rarely used (mostly due to not being able to create new cases) and had a few lingering issues. Dates couldn't be parsed properly from excel and most of the javascript was no longer working due to outdated selectors.

### Make the UI more consistent with the rest of the application

#### =========== Old ===========
![screen shot 2013-05-21 at 2 50 12 pm](https://f.cloud.github.com/assets/152134/556148/e8ad343e-c3d1-11e2-979f-ff88253d4cb7.png)

![screen shot 2013-05-23 at 1 57 24 pm](https://f.cloud.github.com/assets/152134/556160/4657e980-c3d2-11e2-8eba-ed39c5cfc874.png)

#### =========== New ===========
![screen shot 2013-05-23 at 1 55 24 pm](https://f.cloud.github.com/assets/152134/556149/f50096d6-c3d1-11e2-9de0-30bba3748fca.png)

![screen shot 2013-05-23 at 1 57 30 pm](https://f.cloud.github.com/assets/152134/556161/4b28fd6e-c3d2-11e2-89ba-44c0726bab7f.png)