add block handler to handle block files on different under file systems
add BlockHandlerHdfs as stub
* Created TACHYON_CLASSPATH to hold a dynamically generated classpath.
* Updated shell scripts to use TACHYON_CLASSPATH
* Added HADOOP_HOME to point to a local hadoop installation.
* Generate Tachyon + Hadoop CP if HADOOP_HOME is defined
* Updated the default JAVA path in linux to the generic symbolic link (will support most JREs without additional config)
Use a generic method to establish the hadoop classpath.  Requires hadoop command in classpath and works with 1.x and 2.x
Revert the JAVA_HOME setting.
Trying to fix HBase support issue in TACHYON-27
change isHadoopUnderFS() in UnderFileSystem to be public, and use it in BlockHandler
modify comment format and gramma mistakes
some format fix
for real revert JAVA_HOME change.
Optimize imports; reformat code style; improve javadoc; remove the commented code.
Linked to TACHYON-46 in Javadoc
remove deprecated warnings
Improve Javadoc comments
Merge branch 'amplab'
Changes for TACHYON-64
Merge pull request #342 from mubarak/TACHYON-64

[TACHYON-64] Typo in INFO log messages in DataServerMessage
update JIRA URL in pom.xml
TACHYON-54 Support HBase.
TACHYON-27 Temporary implements createNonRecursive function.
Merge pull request #346 from uronce-cc/updateJIRA

update JIRA URL in pom.xml