base: add trace startup-code to _main()
foc: add trace_buffer Cpu_session interface
foc: add trace_buffer start-up to Thread_base
base: add name() to struct rpc_name

Thereby one can get the actual name of the rpc function which is needed
by TRACE.
base: add TRACE-hook to rpc_client
noux: add tb_dataspace() to Cpu_session_component
Add trace + trace_session tests
os: add Trace_fs
noux: short-cut for read(..., 0)

If the bytes left to read are 0 we drop out early w/o involving the
packet-stream.
core: fix labelling policy in Log
foc: add _session_label to Cpu_session_component
core: add _session_label to Cpu_session_component
core: use label for init's Cpu_session
noux: add missing local service

Use a local CPU service to prevent a redirection to noux' parent (in
this case init which does not know noux' local capabilities).
base: split member in Trace_buffer

Since there is currently still a problem if the Trace_buffer struct
is bigger than 156 bytes the member 'label' is split in 'label'
and 'name' to be able to use both.
base: add backlog handler to Trace facility + name
base: rename Evbufentry in Trace_session test
base: rename Evbufentry to Trace_event in Registry
base: rename Evbufentry in Trace_buffer
base: add RPC trace-point