Implement 'default_file_action' client option that can be set to 'transfer' (default) or 'none'. When set to none, inputs and outputs are not transferred over HTTP, they are passed through unchanged or copied directy (in the case of working directory files since LWR uses a different working directory).

Add new abstraction for finishing up job that will hopefully allow for better testing by moving more logic previously in LWR galaxy runner into LWR client modue and tested in test/check.py.