Changed --registry flag from "log_storage" to "replicated_log" to be more descriptive.

Review: https://reviews.apache.org/r/21019
Added a metric for the size of the registry.

Review: https://reviews.apache.org/r/21021
Exposed the event queue in ProcessBase as protected.

Review: https://reviews.apache.org/r/20991
Added metric for event queue size in the master.

Review: https://reviews.apache.org/r/21032
Fixed SlaveRecoveryTest.RestartBeforeContainerizerLaunch.

Review: https://reviews.apache.org/r/21007
Fixed typo in master's log message.
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