Add SetupEntityAccess comparison to UI

Adding SEA compare panels for common, unique and differing perms. Calls getSetupEntityPerms and displays results in appropriate panel. 

Also, implement caching for SetupEntityIds associated to permission sets and also cache SetupEntity names/labels to prevent multiple queries. 
![screen shot 2013-10-08 at 12 10 04 pm](https://f.cloud.github.com/assets/2161427/1292030/480f69e6-304d-11e3-8687-9b113adeffb2.png)