Make the conf/slaves as a gitignore file
Merge pull request #507 from PasaLab/TACHYON-207

[TACHYON-207] Make the conf/slaves as a gitignore file
Simple fix for typo from tachyon.worker.network.netty.buffer.recieve to tachyon.worker.network.netty.buffer.receive
vagrant deploy: various bug fixes.
- Change Hadoop download site to archive.apache.org for better locality
- fix hostname issue in /etc/hosts that makes HDFS NN binds to 127.0.0.1
and other cannot connect

Signed-off-by: rootfs <hchen@redhat.com>
Merge pull request #508 from hsaputra/fix_typo_netty_config_receive

Simple fix for tachyon.worker.network.netty.buffer.recieve
Merge pull request #509 from rootfs/fix-hdfs2

vagrant deploy: various bug fixes.
Add StorageTier into Tachyon
fix some typo and format
merge hierarchy code into Tachyon
format
refactor promote block
remove DropAfterPromote configuration
clean code and some bug fix
remove getBlockFileInfo interface - thrift change
remove getBlockFileInfo - non-thrift change