Updated indentation in libprocess configure.ac.
Updated indentation in Mesos configure.ac.
Updated stout to satisfy whitespace/indent.

Review: https://reviews.apache.org/r/21004
Updated Mesos to satisfy whitespace/indent.

Also modified cpplint.py to check that access keywords are NOT
indented and enabled the cpplint rule in mesos-style.py.

Review: https://reviews.apache.org/r/21005
Updated stout to satisfy whitespace/line_length.

Review: https://reviews.apache.org/r/20976
Updated libprocess to satisfy whitespace/line_length.

Review: https://reviews.apache.org/r/20977
Updated Mesos to satisfy whitespace/line_length.

Also enabled the whitespace/line_length cpplint rule.

Review: https://reviews.apache.org/r/20994