Implemented Ant Task and also fixed error handling issue

At my company, my project team forked this repository locally to implement an Ant wrapper (easily used in ant as well as embedded in maven).  Additionally we made some light modifications to the logging and fixed an issue where most errors from mongodb were not being reported (see db.eval() use for details).

Hopefully you wont have any trouble merging this series of changes in, but if you do please let me know and I will try and create a simpler patch to send.