Fixes #33 (mesos-ec2 -> spark-ec2), some word-smithing, adjusts spacing, remove .collect() function at one point in code.
Merge branch 'master' of github.com:amplab/training
Adjusting more spacing in K-Means section.
Merge branch 'master' of github.com:amplab/training

Conflicts:
	strata_2013/index.md