replace generator with imap object

Allows deeper debugging while maintaining laziness
replace generator in run with it.imap

helps with debugging
dispatch reify
dispatch unify
replace {as,from}_logpy with operator, arguments, term
clean up - style edits
logify is a class decorator
logify to term.  Split off args, op, term to term.py
add unifiable function
Reduce scope of term.py.  Add MyTerm test
assoccomm uses term, arguments, operator
add unifiable to top level import, fix example
relative imports
print function
depend on toolz for map, range, iteritems, etc....
imports, __name__, and other py3 fixes
div -> truediv
add dependencies section to README
add dependencies.txt
add extension example in README