run: add support to query qemu support

To be used by the base-* specific run/env scripts to choose the appropriate
test backend.
run: introduce explicit wait_for_output

To be used by base-* run/env scripts
run: extend genode_until_run by a spawn id

genode_until_run can be called now with a spawn id to able to reattach to a
spawned process (amt, serial output). Run scripts can now call genode_until_run
multiple times.
run: extend noux to run automatically natively
net: add library for performance measurements
net: net_stat instrumented version of iPXE driver
net: net_stat instrumented version of usb_drv
net: nic session client using net_stat lib

A simple nic session client using the performance measurement library.
run: add nic driver performance test

A run script which sends raw ethernet packets from the host machine to the
target machine. Three tests are implemented:
- The network_stat instrumented driver of usb_drv and net_drv
  are used to get the raw receive performance of the network driver.
- A simple nic_session client is receiving from the un-instrumented network
  driver raw ethernet packets.
- A bridge is added between driver and simple nic_session client.
run: lwip use is_qemu
run: support RUN_OPT for all platforms

Use RUN_OPT="--target ..." to select the backend test method.

Supported values so far:

qemu     - qemu + grub bootloader (default)
qemu+pxe - qemu + pulsar bootloader (PXE)
amt      - Intel AMT (reset+serial output) + pulsar bootloader

Related to issue #598
run: add support to specify 'serial' via RUN_OPT

If the target machine is connected locally one may specify
"serial" as target in the RUN_OPT variable to get the test output.

Used for panda and arndale on foc and hw.
run: add lwip pingpong test using tcp
run: adjust lwip pingpong test for foc_arndale
run: adjust lwip pingpong test for x86
run: update tcp_terminal to run in 64bit setups
run: use kdb_uart and acpi_drv with l4linux

Test now succeeds also on native x86 32bit hardware.
run: add acpi spec as default to foc/nova 64bit
port of netperf server to native Genode
lwip: enable SO_RCVBUF socket option

In issue #313 the SO_RCVBUF was intended to be enabled, however the current
lwip port looks for another define LWIP_SO_RCVBUF instead of LWIP_RCVBUF.

Fixes #716