Add hapidump to print all data provided by a server

[dgarciabriseno]

Adds a utility function to get all information provided by a hapi-server in one command.
It's kind of extreme, but useful I think.

[rweigel]

This looks like a helpful addition.

Currently, we have a process that aggregates all of the metadata from all servers nightly: https://github.com/hapi-server/servers/tree/master/index. The process uses a Jython script run using Autoplot (by @jbfaden), but there has been a discussion about using the Python hapiclient. I'll probably accept this pull request after hearing from @jbfade and then add a keyword option to use one of the files at https://github.com/hapi-server/servers/tree/master/index instead of looping through all datasets, which can take a significant amount of time.