Fixed an incorrect CHECK in MesosSchedulerDriver::stop that assumes
'process' is always instantiated.

From: Jiang Yan Xu <yan@jxu.me>
Review: https://reviews.apache.org/r/16592
Added freeMemory() to stout.

freeMemory() returns amount of free system memory. Can in
combination with memory() be used to get total used memory.
This allows future finer grained break-downs of used memory
in user memory, kernel buffers/caches and so on.

Review: https://reviews.apache.org/r/16569
Added missing includes for linux/cgroups.hpp.

From: Ian Downes <ian.downes@gmail.com>
Review: https://reviews.apache.org/r/16665
Adds Abhishek Parolkar presentation to documentation.
Enabled toggling between relative and absolute timestamps by clicking on them.

Note that your preference for which type you'd like is remembered
between sessions.

Issue: https://issues.apache.org/jira/browse/MESOS-789

Review: http://reviews.apache.org/r/16712

From: Thomas Rampelberg <thomas@saunter.org>
Review: https://reviews.apache.org/r/16712
Showed start/stop time for tasks of completed frameworks.

From: Thomas Rampelberg <thomas@saunter.org>
Review: https://reviews.apache.org/r/16715
Adds Sigmoid Analytics to Powered By page.
Added a configure time check for building a native python egg.

This autoconf check does a rather complex test for covering MESOS-799.

It builds and test-runs a minimal egg that links against a static
library that imports a standard C++ library object. A static library
(built using the standard mesos build settings) is needed in this
puzzle because the egg producing distutils possibly use slightly
different build settings (derived from python-config).

If this check succeeds, we can be rather sure that the mesos-egg
itself will be functional from a build-env point of view.

From: TILL TOENSHOFF <toenshoff@me.com>
Review: https://reviews.apache.org/r/16436
Fixed namespace resolution in slave/paths.hpp.

From: Ian Downes <ian.downes@gmail.com>
Review: https://reviews.apache.org/r/16788
Merge branch 'master' into feature/Debian