Changed the SIGTERM handler to not dump a stacktrace.

Review: https://reviews.apache.org/r/13028
Removed unnecessary sleeping from the test executors.

Review: https://reviews.apache.org/r/12781
Search frameworks & executors successively to save concat

Array.concat creates a new Array, which in this case is used once to
find frameworks and executors and then thrown away. Instead the Arrays
can be searched successively in place without allocating more memory.

Review: http://reviews.apache.org/r/13002
Remove HTML5 shim for <IE9

IE8 and below are officially no longer supported. The shim only loaded
in IE8 and below, and so it can be removed without affecting supported
browsers.

Review: http://reviews.apache.org/r/13005
Fixed comment for Hadoop pending tasks calculation.

The commit 58e6c907497418d was submitted prematurely without this
comment.

Review: https://reviews.apache.org/r/12959
Be more intelligent about slot allocation.

When we get a resource offer, we'll try to be clever about how we
allocate slots to the offers.  Ideally we want to use as much of the
resources available when we have a lot of pending tasks, and we also
don't want to use more resources than we actually need.

Review: https://reviews.apache.org/r/13078
Don't prematurely kill TaskTrackers.

We assign the JobID to the internal Mesos tracker (for the TaskTracker)
rather than the TaskID.

In the case where a TaskTracker has only map tasks assigned to it and
they have all completed, we mustn't terminate the tracker until the
entire job has finished, including the map tasks.

Review: https://reviews.apache.org/r/11119
Kill tasks that never properly launch.

After trying to launch a task tracker, we'll wait up to 5 minutes before
giving up and killing the task.

Review: https://reviews.apache.org/r/11124
Allowed some JVM memory vars to be configured.

Also modified the slot CPU/mem values to be more sane defaults.

Review: https://reviews.apache.org/r/11130
No longer accept offers on the same host/port.

We'll try to find a port combination that hasn't already been used to
launch a TaskTracker.

Review: https://reviews.apache.org/r/13080
Reduced jobtracker logging.

Review: https://reviews.apache.org/r/12923
Removed /vars endpoints from the Master and Slave.

Review: https://reviews.apache.org/r/13048
Added /health endpoints to the Master and Slave.

Review: https://reviews.apache.org/r/13049
Added help for the /master/redirect endpoint.

Review: https://reviews.apache.org/r/13076
Updated the launcher to redirect stderr/stdout during forked setup.

Review: https://reviews.apache.org/r/13177/
Update email addresses for the dev list.

Change references of 'mesos-dev@incubator.apache.org' to
'dev@mesos.apache.org'. Also, changing
'mesos-dev-subscribe@incubator.apache.org' to
'dev-subscribe@mesos.apache.org'.

From: Matthew Silvey <matthew@dancewithdevils.com>
Review: https://reviews.apache.org/r/12980
Revert flag environment variable semantics.

Now environment variables will be "tried" to be applied as flags but
if no flag is known given an environment variable then the loader will
not fail.

Review: https://reviews.apache.org/r/13173
Added MESOS_NATIVE_LIBRARY to launcher.

Review: https://reviews.apache.org/r/13174
Set MESOS_NATIVE_LIBRARY in the testing environment.

We want to force our tests (including the Java ones) to use the most
recent version of our library, so we set MESOS_NATIVE_LIBRARY.

Review: https://reviews.apache.org/r/13175
Cleaned up the pre-installed "wrappers".

Review: https://reviews.apache.org/r/13176