Don't set "pipefail", it changes behaviour!

Don't set "pipefail", it changes behaviour!

Using "pipefail" is a good idea (fail early), but changes behaviour
and leeds to undesired side-effects when commands exit because of the
PIPEFAIL signal (exit code 141).

References:
 - https://stackoverflow.com/questions/19120263/why-exit-code-141-with-grep-q
 - http://www.tldp.org/LDP/lpg/node20.html
 - http://www.pixelbeat.org/programming/sigpipe_handling.html

This partially reverts commit 2177f5af642e.