Rename ni_process_buffer.capture to .active

Signed-off-by: Olaf Kirch <okir@suse.de>
Fix the copyright notice to include 2014

Signed-off-by: Olaf Kirch <okir@suse.de>
Remove ni_process_run_and_capture_output()

Signed-off-by: Olaf Kirch <okir@suse.de>
ni_process: rely on SIGCHLD rather than closing of stdout/stderr when monitoring for process exit

Signed-off-by: Olaf Kirch <okir@suse.de>