validate Token and pk__token filter parameters
update validation of Token use at query-execution time
pass partition columns to Token for use serializing values
verify SELECT statement generation with token() works now
add tests to verify Token and pk__token validation
adding test around token values
Merge branch 'fix_token_comparison' of https://github.com/russellhaering/cqlengine into issue-132
Use CL.ONE explicitly when interacting with the system keyspace

The system keyspace uses  "LocalStrategy" for replication so it needs to
be accessed with CL.ONE. If the default consistency level is set to
something else all management commands which rely on introspecting the
system keyspace will fail.