seoul: Patch executor/build_instructions.py

We need to specify the actual python version in the build_instructios.py
script too.
libports: update zlib to version 1.2.8

Fixes #741.
Spelling fix
Add missing session route to printf.run
core: Be more precise in IO_MEM error message
base-hw: Avoid early calls of cmpxchg

This patch eliminates calls of 'cmpxchg' prior enabling the MMU. This is
needed because the 'ldrex' and 'strex' instructions do not always work
with MMU and L1 cache disabled, i.e., on Raspberry Pi.
base-hw: Make memory_region_attr CPU-specific

This patch moves the implementation of the 'Arm::memory_region_attr'
function from the generic ARM code to the ARM v6/v7 specific code
to enable the customization of page-table bits depending on the
specific CPU core type. I.e., the ARM1176 apparently does not cope
well with setting the 'Tex::bits(2)' for MMIO mappings.
base-hw: Enable caches on ARM v6
base-hw: Support for Raspberry Pi
run: add support to run noux_net_netcat natively
run: support native l4linux test on panda/arndale
run: add succeeded message to network_test
autopilot: redirect stderr to log file
tool: create appropriate build.conf for hw_arndale
autopilot: option to keep existing test directory
run: extend lwip test for arndale board
vancouver: handle CPUID 0x40000000

This instruction is issued by Linux when the KVM guest support is
compiled in. We have to return deterministic values to let the Linux
kernel survive.
Utility for synchronizing interface calls
vancouver: Avoid busy startup synchronizations
vancouver: Improve locking scheme

This patch replaces the error-prone manual locking with the use of the
'Synced_interface' for the motherboard and the VCPU dispatcher. It also
removes all globally visible locks. Locks are now explicitly passed to
subsystems when needed.