core: TRACE service interface and implementation
linux: add expanding Cpu_session_client
seoul: fix region conflicts

At least 64bit Seoul dies with Region_conflict reliable and reproducible.

When during startup of Seoul some Genode code (caused by executing some
constructors) try to attach a region, the region manager code in the rm_session
will try to place the attachment at the smallest large enough aligned free
virtual region.

For now, I observed one attachment causing trouble (but not knowing who causes
this - it does also not really matter). The questionable region is 0x4000 of
size for 32bit and 0x8000 of size for 64bit.

To steer the region manager a bit, we try now following trick:

With this commit the load address of the binary for 32 and 64 bit is moved
close to the end of the virtual address space, but leaving enough free virtual
space for the above observed attachment (and a bit more).

The region manager code now will try to fill up the virtual region behind
the binary up to the end of the virtual address space, effectively letting the
lower virtual region untouched - hopefully.

Works for now, but it will break again - for sure.

Fixes #519
seoul: update to recent seoul branch

Required to use intel82576vf in 64bit host mode
seoul: add intel82576vf for 64bit
seoul: fix run script issues 823 and 824

Fix #823
Fix #824
seoul: add test for native runs

and add to autopilot list.
seoul: add invalid guest state handling
qt5: hook for selectively inhibiting qt5 builds
doc: Update components.txt and top-level README