run: check for netperf version in user environment

For native Genode netperf port.
run: split native Genode netperf script

Split the netperf run script into 3 ones so that it can be used more easily
in an automated run.

netperf.run        - use native nic driver (x86) or usb2.0 (arndale, panda)
netperf_usb30.run  - use native nic driver (x86) or usb3.0
netperf_bridge.run - use native nic driver (x86) or usb3.0 (arndale) and bridge

Issue #794
run: check for netperf version in user environment

For L4linux version on foc_arndale.
run: split netperf l4linux script

Split the netperf run script into 3 ones so that it can be used more easily
in an automated run.

It is solely for foc_arndale by now.

l4linux_netperf.run        - use nic via usb2.0
l4linux_netperf-usb30.run  - use nic via usb3.0
l4linux_netperf-bridge.run - use nic via usb3.0 + bridge
run: prepare netperf l4lx output for post processing

Issue #794.
run: add netperf tests to autopilot list

* native Genode (using lwIP) netperf
as
* L4Linux netperf
base-hw: disable L2 cache on Pandaboard (fix #797)

* Fix bitfield typo in TTBR0 register for ARMv7
run: check size of reported disc in part_blk

Triggers bug if LBA48 mode is used.

Issue #761
atapi_drv: Implement LBA48 specific block count

Use NATIVE MAX ADDRESS EXT to retrieve last block for LBA48. Also check not only
for enabled LBA48 support but for the 'host protected area' bit before using the
LBA48 version. This is because the high order byte (HOB) data retrieval is
broken in Qemu.

Fixes #761.
Add -mcpu flag to ARM CPU spec files (Ref #797)

When using certain assembler instructions, e.g. 'smc' that are
only available on some CPUs of the same architecture like ARMv7a,
it's necessary to specify the target CPU for the assembler. Otherwise
it will complain about.
run: disable network tests for imx53

We have no network driver on this platform by now.
Disable noux run script for i.MX53 platform

This platform misses necessary UART driver support.
run: add success message to lx_hybrid_pthread_ipc
Disable run test for base-hw as long as it fails

Ref #801
Start receiver thread in LwIP after initialization

Otherwise the receiver thread might access variables not initialized properly,
and thereby raising pagefaults.

Fixes #802
base-hw: preserve symbolic link bin/core

In this case "mv A B" works slightly different than "cp A B; rm A" as
symbolic links come into play. The statements should copy the contents
of A into the symboliv link at B (preserving it as is) and remove A. The
mv would replace the link B by the binary A.

Fixes #805.
base-foc: Improve documentation of capability enums

Fixes #568
base-hw: use generic signal_session/connection.h

base-hw extended the signal quota in a specific connection
implementation, which just conceals other issues if quota upgrade is
triggered.

Fixes #410.
run-tool: unify building of u-boot image (fix #807)
run-tool: be more failure tolerant in spawn_serial

Fixes #809