hw: use reliable start message in run env

Previously for determining wether boot-up succeeded or not, we looked
for a message that is switched off in release mode. Now the kernel
provides a reliable message as soon as initialization is done.

ref #1096
noux: make RM replay less noisy in release mode

As the message "replay: missing dataspace info for ..." occurs multiple times
on every fork, it slows down at least noux_tool_chain_auto with hw_arndale
about 10 seconds. To avoid this overhead in release mode I've turned it into a
warning rather than an error.

ref #1096
hw: make kernel less noisy in release mode

In most cases an error report is not necessary in the kernel as the problem
does not affect the kernel itself but the according user-land context. Thus
we can also do a warning that is not printed in release mode and hence safe
execution time.

ref #1096
hw: make RM faults less noisy in release mode

If an RM fault ends up in any trouble, the faulter remains paused and
the pager activation continues with the next fault. Thus we can print
a warning instead of an error and safe execution time in release mode.

ref #1096
hw: reduce stack size of idle threads

ref #1096
hw: faster Kernel::Signal_receiver::_listen()

ref #1096
hw: move core-restricted interface to local header

fix #1096
hw: remove unused kernel_pd_alignm_log2

ref #1101
hw: rename mode_transition_virt_base

ref #1101
hw: correct return type of Kernel::new_thread

ref #1101
hw: comment result of Kernel::route_thread_event

ref #1101
hw: simplify result of Kernel::access_thread_regs

ref #1101
hw: simplify buffer of Kernel::access_thread_regs

ref #1101
hw: correct result type of Kernel::new_vm

ref #1101
hw: don't use assert in Kernel::pause_thread

ref #1101
hw: don't return a result in Kernel::pause_thread

ref #1101
hw: split pause_current_thread from pause_thread

Kernel::pause_current_thread can be implemented much simpler and is not
restricted to core threads, in contrast to Kernel::pause_thread which
also benefits from the split and can be moved to core_interface.h.

ref #1101
hw: don't use assert in Kernel::start_thread

ref #1101
hw: don't use assert in Kernel::bin_thread

ref #1101
hw: don't use assert in Kernel::update_pd

ref #1101