Service for getting Evaluation Info from the cache 

Grabs basic eval info like scale and question length info and also holds all question info (prompt, order, etc).  Global evaluation data is stored separately in a single cache entry that will apply to all evaluations, and it uses the same structure as the eval info.

Since we already have a classTime cache service, we need to find a place to put rosters and teacher information so we will have everything we need in the cache for a specific eval.  I'd vote for just doing a multi-query and sticking that all in the classTime object.