Fixed Issue #1194

Hopefully finished issue #1194.

Grade entry items should keep the order they are added/uploaded in:
- added position to grade_entry_items
- position for new columns are being added in the controller before saving (based on name in POST request because name is based on the time the link to add a new column was clicked)

Upload csv should:
- link grades to column names
- delete old column names not in csv file
- delete old grades associated with old column names

Tests should run and more are added for additional csv functionality and to test position setting

Column names added manually:
![screen shot 2013-11-11 at 4 46 07 am](https://f.cloud.github.com/assets/2425730/1512610/95b11888-4acf-11e3-92e6-21f3e99de409.png)

Same grade entry form after CSV upload:
![screen shot 2013-11-11 at 4 46 42 am](https://f.cloud.github.com/assets/2425730/1512608/90142082-4acf-11e3-873f-6308f175242d.png)