Merge pull request #36 from pwendell/v2

V2
update to use tachyon 0.4.0
use s3 to download tachyon jar
Merge remote-tracking branch 'upstream/v2' into v2
Merge pull request #39 from haoyuan/v2

Upgrade Tachyon to v0.4.0
update tachyon to 0.4.1
Merge pull request #40 from haoyuan/v2

update tachyon to 0.4.1
download tachyon tar files from s3 instead of github.
Merge pull request #41 from haoyuan/v2

download tachyon tar files from s3 instead of github.
Added referecences to 0.9.1 binaries.
Merge pull request #44 from tdas/v2

Added referecences to 0.9.1 binaries
Add Shark 0.9.1 support
Add popd's before returning in shark/init.sh
Merge pull request #45 from harveyfeng/v2

Add Shark 0.9.1 support
Added SPARK_WORKER_INSTANCES and SPARK_WORKER_CORES support
Added SPARK_MASTER_OPTS configuration
Added spark_master_opts to README
Avoid workers with no cores when over-subscribing workers
Merge pull request #46 from douglaz/configurable_workers

Configurable workers
HOTFIX: Backwards-compatiblity fix for #46