Sjang92/advanced settings feedback

@jrbl  @njdup

There were no validations being done in Studio's course advanced settings tab. 
Now course instructors receive feed back as a list of settings changes that has formatting/value errors.

![screen shot 2014-07-16 at 4 13 13 pm](https://cloud.githubusercontent.com/assets/3598201/3606958/e8fe92b8-0d3e-11e4-8fe6-b861b0a8b3d4.png)

This file above is actually a fix for an existing test due to a problem caused by this new functionality. Actually, the error messages that are being printed out are pulled directly from the xblock repo (field validation for xblocks). I could wrap those default error messages just like the way you suggested. Do you want me to do that?