Updated the CHANGELOG for releasing 0.17.0.
Logged ZooKeeper session expiration event in group.
Fixed ROOT_CGROUPS_Write test.

Review: https://reviews.apache.org/r/18532
*** Modified for 0.18.0-rc3 *** Enforced log coordinator demotion
after a write is discarded.

Review: https://reviews.apache.org/r/18488
Fixed incorrect stderr to stdout pipe routing in configuration phase.

Review: https://reviews.apache.org/r/18608
Added a test for CFS cpu limits in the cpu isolator.

Review: https://reviews.apache.org/r/18276
Renamed Cfs test to properly disable in non-root non-linux environment.

Review: https://reviews.apache.org/r/18634
Fixed Cpu isolator to use integral values for cfs quota.

Review: https://reviews.apache.org/r/18639
Refactored cpu control writes.

Review: https://reviews.apache.org/r/18642

Conflicts:
	src/linux/cgroups.cpp
*** Modified for 0.18.0-rc4 **** Only darwin/clang needs GTEST to
supply its own tr1 tuple.

Review: https://reviews.apache.org/r/19077

Conflicts:
	3rdparty/libprocess/configure.ac
	configure.ac
Switched to cxx11 by default for libprocess.

Review: https://reviews.apache.org/r/18577
Switched to cxx11 by default for mesos.

Review: https://reviews.apache.org/r/18576
Fixed fetcher to properly fetch multiple URIs.

Review: https://reviews.apache.org/r/18974
Added test for subprocess with environment variable set.

Review: https://reviews.apache.org/r/19144
Updated CHANGELOG for 0.18.0-rc4.
Patched glog to compile demangle.cc with clang.

Review: https://reviews.apache.org/r/18307
Fixed build failure of Python-Egg on OS X and clang 3.4.

Workaround for incompatibility of clang 3.4 with build settings of
Apple's Python distribution. Adds PYTHON_CFLAGS and PYTHON_CPPFLAGS to
configuration phase. Those variables are pre-populated by the contents
of CFLAGS and CPPFLAGS. When clang is used for the compilation, the
-Qunused-arguments override is added to both variables to deescalate
possible errors caused by unknown commandline flags towards warnings,
thus allowing to build our Python egg with clang 3.4 (Xcode 5.1) and
Apple's default Python.

Review: https://reviews.apache.org/r/19068
Force disable C++11 in libprocess for g++-4.7.

Review: https://reviews.apache.org/r/19335
*** Modified for 0.18.0-rc5 *** Force disable C++11 in mesos for
g++-4.7.

Review: https://reviews.apache.org/r/19336
Merge tag '0.18.0-rc4' into 0.18.0-integ