Low: services: restore SIGPIPE default behavior for child processes

Commands in OCF scripts behave slightly differently when SIGPIPE
is ignored versus when SIGPIPE is handled by the default behavior.
It is best to launch OCF scripts without SIGPIPE being ignored
by the environment, and let the scripts themselves handle SIGPIPE
however they want.
Merge pull request #566 from davidvossel/sigpipe-dfl

Low: services: restore SIGPIPE default behavior for child processes