Merge pull request #54 from pwendell/v2

Add support for r3 instances
Porting ext4 changes into v2 branch
add spark-0.9.2 to v2
Merge pull request #61 from mengxr/spark-0.9.2-v2

add spark-0.9.2 to v2
map shark-0.9.2 to shark-0.9.1
Merge pull request #62 from mengxr/shark-fix

map shark-0.9.2 to shark-0.9.1
HOTFIX: Adding Spark 1.1.0
BUGFIX: Remove extra * in Spark init script