D-ITG control: Catch errors when killing subprocesses.
Remove ancient unused config code from main netperf-wrapper executable.
Ensure default settings are not modified when loading hosts etc.
Make aggregators store the settings object as an object property.
D-ITG control: Make sure bytes are passed trough the IPC pipe.
D-ITG control: Fix return key from request_new_test().
Add D-ITG runner (works but still incomplete).

The runner talks to the control server to negotiate a session and
retrieve results after the test has run. Can still only output one data
set (bitrate) from the captured data. Proof of concept ditg test included.