Move path and link_name related functions and regex patterns to a new soc/logic/path_linkname.py module, and fix all dependencies. path/link_name functionality is becoming the generic way to identify entities in the Datastore in a URL-compatible way.

from query import *
from subqueries import *
from where import AND, OR
from datastructures import EmptyResultSet

__all__ = ['Query', 'AND', 'OR', 'EmptyResultSet']