Created example using socrates data and agent for experimentation

Hi @cosmoharrigan, I put a new agent in the attention directory to be better able to modify it.
I'm loading it from the socrates file and just running some steps to check if it's working properly. It seems to be working; however, I get a lot of atoms like this:
```
(InheritanceLink (av 0 0 1)
    (VariableNode "$pln_var_xxxx")
    (VariableNode "pln_var_yyyy")
)
```
Is there a way to filter them out as they obstruct the rest of the relevant atoms?
Please put this agent (socrates_agent.py) in the opencog repository, since it has the Cython bindings as a dependency.