Used 'Owned' instead of shared_ptr and cleaned up some formatting.

Review: https://reviews.apache.org/r/10110

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1468768 13f79535-47bb-0310-9956-ffa450edef68
Refactored slave::Framework/Executor. Included "states" as well as
added recovery methods.

Review: https://reviews.apache.org/r/10111

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1468769 13f79535-47bb-0310-9956-ffa450edef68
Moved slave::Framework/Executor implementation into slave.cpp.

Review: https://reviews.apache.org/r/10112

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1468770 13f79535-47bb-0310-9956-ffa450edef68
Fixed slave to explicitly check for framework and executor states.

Review:  https://reviews.apache.org/r/10142/

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1468771 13f79535-47bb-0310-9956-ffa450edef68
Fixed status update manager to explicitly handle checkpointing and
non-checkpointing updates.

Review: https://reviews.apache.org/r/10438

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1468772 13f79535-47bb-0310-9956-ffa450edef68
Fixed slave to properly schedule work and meta directories for
garbage collection.

Review: https://reviews.apache.org/r/9997

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1468773 13f79535-47bb-0310-9956-ffa450edef68
Fixed the slave to wait for all executors to exit and delete the
"latest" slave symlink when shutting down.

Review: https://reviews.apache.org/r/10233

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1468774 13f79535-47bb-0310-9956-ffa450edef68
Added states to Slave struct.

Review: https://reviews.apache.org/r/10268

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1468775 13f79535-47bb-0310-9956-ffa450edef68
Fixed slave to properly figure out a command executor.

Review: https://reviews.apache.org/r/10278

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1468776 13f79535-47bb-0310-9956-ffa450edef68
Fixed slave to properly schedule/unschedule top level executor
directories for garbage collection.

Review: https://reviews.apache.org/r/10413

git-svn-id: https://svn.apache.org/repos/asf/incubator/mesos/trunk@1468777 13f79535-47bb-0310-9956-ffa450edef68