Add StorageTier into Tachyon
fix some typo and format
small fix for getting block size
Fixed the userId changing issue [TACHYON-171]

The problem is that if a user opens a client connection and starts
writing a file, but finishes writing after a certain
timeout (user.master.client.timeout.ms), then the MasterClient will
close its connection before the file is written, then reconnect and get
a new userId, which will screw up the write.

I'm not quite sure why we automatically close the connection if it
hasn't been used for a while, as we aren't really wasting any resources
by keeping it open. This change removes the original heartbeat
mechanism, which tracks how recently the client has been used and closes
the connection automatically, with a heartbeat that pings the master to
check the connection, and closes the client only if it can't connect to
the master. Now on a long write (or any operation with the client that
takes longer than user.master.client.timeout.ms), we won't reconnect and
change the userId.
simplify code path of converting String to enum in StorageLevelAlias
Documentation fixes
Undid the changes to MasterClient retry logic
vagrant deploy: add hdfs 1 as underfilesystem

Signed-off-by: rootfs <hchen@redhat.com>
Fixed more issues found by findbugs
review feedback

Signed-off-by: rootfs <hchen@redhat.com>
set tachyon.web.resources to PathToCore/src/main/webapp before initilize TachyonMaster in LocalTachyonMaster
fix missing hdfs 1.x datanode

Signed-off-by: rootfs <hchen@redhat.com>
TACHYON-210 Checkstyle check fails if you run inside a core module.
Merge pull request #505 from SiyuanHe/set_webapp_dir_tachyon-185

[Tachyon-185] set tachyon.web.resources to PathToCore/src/main/webapp before initilize...
clear tachyon.web.resources property when closing LocalTachyonMaster
Merge pull request #506 from hsaputra/TACHYON-210_fix_location_checkstyle_suppression

TACHYON-210 Checkstyle check fails if you run inside a core module.
Merge pull request #503 from dcapwell/morefindbugissues

Fixed more issues found by findbugs
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