tests for measuring network performance

The branch contains run scripts adjustments to run more test automatically on native hardware (x86, arm boards Panda and Arndale).

Additionally following network tests are added:

Network Pingpong test by Josef and Christian automated to run automatically on native hardware.

raw packet Ethernet test 
- Linux client sends via a raw socket packets to a Genode target. Currently solely the receiving part on the Genode target is supported.
- On Genode a simple library are used to look for magic packets to start/stop a test run.
- The library is hooked into a separate test instance of the ethernet network drivers
-- "nic_drv_stat" for dde_ipxe on x86, "usb_drv_stat" for dde_linux on arm
-- into a simple Nic_session client to measure overhead introduced by the session interface and protection domain switches
- Tested for x86-foc/nova, panda-foc/hw, arndale-foc/hw.

Port of netperf tool (http://www.netperf.org/netperf/)
- server side of netperf tool

Add RFC 1323 feature to LwIP stack. Netperf TCP_STREAM shows throughput on panda/arndale platform above >90Mbit TCP stream (100 MBit ethnernet).