Preliminary Addition of CosmoSim Simulation Database Query Tool

This it my first pull request of the addition of simulation datbase query tools to astroquery. As it stands, things are in rough shape, but I welcome all comments, concerns, and tips. Thanks!
this needs to be `print()` for py3 compatibility, or better yet `log.warn()` or `log.info()` depending on how severe this is  - looks like `log.info()` would be appropriate