Ensured ExecutorInfo.framework_id is set.

This includes an update to the Scheduler Driver to set framework_id
on launchTask requests, as well as a change to the Slave to set
framework_id when generating ExecutorInfos for Command Executors.

Review: https://reviews.apache.org/r/13455
Fixed typos in scheduler.hpp and test_framework.py.

From: Yashwanth Nannapaneni <yashwanth620@gmail.com>
Review: https://reviews.apache.org/r/13448
Updated glog to 0.3.3.

This fixes a build issue with clang.

From: Vinson Lee <vlee@freedesktop.org>
Review: https://reviews.apache.org/r/13473