Removes objectTypeModelMap to reduce circular dependency.

refs #2455

- also note areas where we still have lazy loading of modules.
We're trying to avoid lazy requires as that is a bad code smell.  It's not bad per-say, but we shouldn't have to require that for ghost to run properly.

Looks like we can safely move this to the top thanks to 52299998e2fb3fc762c87f1b9df83d40f74b9d72.  Nice catch!