Fixed a flaky use of FUTURE_DISPATCH.
Allowed timing of Future completions in Timer.

Review: https://reviews.apache.org/r/20593
Improved timing accuracy in the Registrar.

Review: https://reviews.apache.org/r/20897
Adds Netflix to #PoweredByMesos list.
Updated the 'contains' method in stout IntervalSet to support more
types.

Review: https://reviews.apache.org/r/20898
Added stream functions for stout Interval and IntervalSet.

Review: https://reviews.apache.org/r/20900
Introduced base64::encode/decode in stout.

Review: https://reviews.apache.org/r/20885
Decode percent-encoded paths.

See MESOS-1164.

Review: https://reviews.apache.org/r/20929
Fixed gcc-4.8 compilation error for stout interval set.

We are hitting the "Unqualified lookup in templates" issue in stout
interval set: http://clang.llvm.org/compatibility.html#dep_lookup

And looks like this is a boost bug:

1) boost/icl/concept/interval.hpp:621
  -- defines a template that uses 'lower_less_equal'

2) boost/icl/concept/interval.hpp:877
  -- 'lower_less_equal' is defined here

Since lower_less_equal does not contain any class type, the compiler may
or may not choose to reject the program according to the C++ standard :(
Clearly, gcc-4.8 rejects the program and gcc-4.4 does not.

I am using a workaround here to bypass the problem.

Review: https://reviews.apache.org/r/20935
Temporarily disabled ExternalContainerizerTest.Launch due to
MESOS-1257.
Add 'value' and 'units' methods to Duration subclasses.

Review: https://reviews.apache.org/r/20922
Used Duration subclasses to allow Timer users to specify units.

Review: https://reviews.apache.org/r/20923
Added template parameter to Timer.

Review: https://reviews.apache.org/r/20925
Temporarily disabled SlaveRecoveryTest.RestartBeforeContainerizerLaunch due to MESOS-1273.
Improved log messages in master.

Review: https://reviews.apache.org/r/20932
Ignored the log write request to a position if it has already been
learned.

Review: https://reviews.apache.org/r/20934
Applied four space indents (PEP8) to Python example frameworks.

Review: https://reviews.apache.org/r/21008
Updated the Registrar to abort permanently upon encountering a Failure.

It's possible for a backed-up master (many items in its queue) to have
many operations enqueued in the Registrar.

In this event, the Master won't commit suicide until the initial
failure is processed. However, in the interim, subsequent operations
are potentially being performed against the Registrar. This could lead
to fighting between masters if a "demoted" master re-attempts to
acquirelog-leadership! This scenario can occur if the "demoted" master
has a large queue and the demotion event is towards the back of the
master's queue.

It would be preferable to ensure that after losing log leadership,
the "demoted" master does not try to re-acquire log leadership and
write to the log.

Review: https://reviews.apache.org/r/20981
Fixed slave authentication to prevent sending TASK_LOST on
disconnection.

Changed master to only remove a slave's frameworks and offers on
exited, not on reauthenticate. Still disconnects at the allocator in
both cases.

Review: https://reviews.apache.org/r/21017
Changed --registry flag from "log_storage" to "replicated_log" to be more descriptive.

Review: https://reviews.apache.org/r/21019