Ignored the recovery error due to the inability to
find the latest executor run.

Review: https://reviews.apache.org/r/14001
Update Powered By page to reflect new organizations using Mesos.
Adds new documentation page to include links to videos and slides for Mesos presentations.
Fixed the broken OsTest.process and OsTest.killtree tests.

Review: https://reviews.apache.org/r/14072
Hid links to dead slaves to prevent dead links.

If a slave is gone, the framework page will print "Slave gone" in place
of the links to the slave's UI. The links would previously fail in
redirection and return the user to the Mesos root page, which is
unpleasant.

Fixes: https://issues.apache.org/jira/browse/MESOS-650

Review: http://reviews.apache.org/r/14074
Removes 90 day plan from documentation, which is no longer relevant.
Updates formatting of heads on Mesos presentations documentation.
Cleaned up some log and CHECK messages.

Review: https://reviews.apache.org/r/14135
Fixed broken build on GCC 4.8 due to -Wall.

With GCC 4.8, Boost fails to build from '-Wunused-local-typedefs', which
is implied by '-Wall'.

Review: https://reviews.apache.org/r/11974/
Simplified os::hostname() in libstout.

Review: https://reviews.apache.org/r/11108
Shuffle offers before sending to frameworks.

This helps ensure fair allocation of resources.

Review: https://reviews.apache.org/r/11121
Added --enable-debug configure flag.

Review: https://reviews.apache.org/r/11605
Slave ping timeout may be increased by flags.

Review: https://reviews.apache.org/r/12885
Turned down noise from ZooKeeper.

Review: https://reviews.apache.org/r/11127
Use hostname instead of IP for redirection.

In the Web UI, the redirection does not work for hosts where the local
interface address is not publicly accessible.  For example, with EC2 the
redirection will not work.

This change writes the Master's hostname into ZooKeeper, thereby
allowing the redirection to work with private IP addresses.

Review: https://reviews.apache.org/r/11975/
On recovery fail, do rm -rf /tmp/mesos/meta.
Use libstout cache for slave completedFrameworks.

The list of retired (completed) frameworks is now a stout cache rather
than a boost circular buffer.  There are now key iterator accessors for
the cache class, and a removal member.

Review: https://reviews.apache.org/r/13599
Added a slave load hint for scheduler sorting.

With this change, the offers will include a slave load hint based on the
5 minute load average for that slave (returned from getloadavg()).
Frameworks can use this hint to select among otherwise similar offers,
as an optimization.

Review: https://reviews.apache.org/r/13675