noux: short-cut for read(..., 0)

If the bytes left to read are 0 we drop out early w/o involving the
packet-stream.
noux: increase the stack size of rpc-ep thread

The current limit (4/8 KiB) is too small when tracing will be enabled.
core: add session label member

This member is used to save the actual session label for further use
within core.
base: add name accessor method to RPC struct

This method may be used to get the actual name of the
corresponding RPC-function.
base: add serialized rdtsc function

Use cpuid instruction to prevent the cpu from reordering the rdtsc
instruction when obtaining the TSC value.

Though it is questionable if "mfence; rdtsc" or "rdtscp" would be
a better choice.
base: add Trace_session header
base: add basic Trace header

This includes the Trace_buffer declaration and definition of most common
functions used to access the buffer and policy.
core: add Trace_session_component
base: add trace accessors to Thread_base interface
base: add tb_dataspace() to Cpu_session interface
base: add tb_dataspace() to Expanding_c_s_c
core: add TRACE
base: add trace startup-code to _main()
linux: add Expanding_cpu_session_client
linux: add Trace_session_component
linux: initial Trace_session support
foc: add trace_session_component to target.inc
foc: add trace_buffer Cpu_session interface
foc: add trace_buffer start-up to Thread_base
foc: add _session_label to Cpu_session_component