Fixed line wrap in state/log.cpp.
Adds Localsensor to PoweredByMesos documentation.
Pass executor directory to Isolator::prepare().

Review: https://reviews.apache.org/r/24177
Serialize isolator prepare and cleanup (reversed).

Review: https://reviews.apache.org/r/25861
Remove /proc and /sys remounts from port_mapping isolator.

Review: https://reviews.apache.org/r/26274
Introduce a shared filesytem isolator.

Isolator supports creating private copies of system directories, e.g.,
/tmp, for each container while sharing the host's filesystem.

Review: https://reviews.apache.org/r/25549
Add Artirix to PoweredByMesos list.
Added --isolation flag for tests.

This is useful to test custom isolation modules with the test suite.
The user can specify the available modules with --modules and then he
can specify the isolator module with the --isolation flag.
With these flags, the test suite will run all tests with the specified
isolator modules.

Review: https://reviews.apache.org/r/26797
Added support for module-specific command-line parameters.

The Modules protobuf is enhanced to support key-value parameters based
on mesos::Parameter and mesos::Parameters.

Bumped Module API version since we modified the signature of the
create() method.

Review: https://reviews.apache.org/r/27051
Added support for both 1.8 and earlier versions of svn library.

Review: https://reviews.apache.org/r/27243
Add Groupon and LIFX to PoweredByMesos documentation.
Include changes to isolation flag when creating Mesos containerizer.
Move Linux namespace functions into linux/.

Also moved and updated tests.

A following commit will remove this code from stout.

Review: https://reviews.apache.org/r/27091
Add getns() for namespaces.

Review: https://reviews.apache.org/r/27127
Add ns::pid::destroy() to destroy a pid namespace.

All processes are signalled with SIGKILL then reaped. The order of
signalling is not determined, i.e., generally the init pid is not the
first pid signalled.

Review: https://reviews.apache.org/r/25966/
Remove Linux namespace functions from stout.

This code was moved to linux/ in an earlier commit.

Review: https://reviews.apache.org/r/27092
Pid namespace isolator for the MesosContainerizer.

Add namespaces/pid to --isolation slave flag. Places executor into a pid
namespace so it and all descendants will be contained in the namespace.

Review: https://reviews.apache.org/r/25865
Correctly recover pid in Linux launcher.

If the freezer cgroup is absent (if the slave terminates after the
cgroup is destroyed but before realizing) we should still recover the
pid because we check this on destroy().

Review: https://reviews.apache.org/r/27166/
Use pid namespace to destroy container when available.

The Linux launcher will check if a container is running in a pid
namespace and will kill all processes rather than using the freezer.
This approach is backwards and forwards compatible.

Review: https://reviews.apache.org/r/25966
Correct include of linux/ns.hpp in isolator tests.