Add "info" method to return stuff that we currently get via the
tbreport script. The difference is that the info is returned as hashed
arrays (or arrays) instead of as a big print statement. Currently just
the node mapping and link mapping functions (of tbreport) are
supported.

At Jay's request, purge pid/eid/gid from documentation and use/allow
"proj", "exp", "group" instead. Note that pid/eid/gid are still
accepted by the server (cause I won't be able to stop using them!).