Added tests for linx, using sockets.
Added Cross Memory Attach latency test.
Assume process_vm_writev/readev always succeeds.
Give permissions for writing to the parent to the child process.

In some distros the needed capabilities are not transmitted to the child
processes. I don't know if it is a bug because as long as real, effective and
saved GID/UD are the same, the processes should be able to use cross memory
attach.
Added cross-memory attach throughput test, and simple pool implementation.
Add cma_pipe_thr to the Makefile.
pool.c: don't flood the pipe
Added template file for throughtput tests.
Merge branch 'linx-tests'
Merge branch 'cma-tests'
Added LINX tests using signals, as well as zero-copy.
Merge branch 'linx-tests'

Conflicts:
	Makefile
linx_thr.c: missing family type in sockaddr.
linx_thr.c: missing socket family.
Merge branch 'linx-tests'
linx_thr.c: refactor linx sockets test
Merge branch 'linx-tests'
cma_pipe_thr.c: do not fill the pipe.
Merge branch 'cma-tests'
Makefile: reintroduce -O3, which had disappeared...