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)

Hi @sjang92 , Alison from the doc team here. Great start, thank you for including the action for the user to take as well as describing the error.
I'd like this message to be a little more informative and a little friendlier. Specifically, I'd like to identify that the errors are the result of a value with the wrong type being supplied, and make it scan better by avoiding values in angle brackets and capitalized letters mid-sentence. 
Here's what I'm thinking:
"This setting stores .* type values. A .* type value was found. Replace it with .*."
so for your first example it would look like this:
"This setting stores string type values. A float type value was found. Replace it with "None" or a string."
(Is it possible for .* to return something other than "<type 'float'>" for the expected value type? and can "String" be lowercase each time it appears mid-sentence?)