Added search functionality (using AngularJS)

Added in-page search of results per Issue #2, also filtering to only display entities in the /files subdirectory of the bucket -- it seemed the simplest way to firewall the app applicaton from the files themselves, perhaps this can be a configurable option (along with S3 bucket URL setting) later. I also took the liberty of removing jQuery since Angular has a subset of the core jQuery functionality, but feel free to add it back in.

Thanks,
Steve