fix a bug in UnderfsUtil.loadUnderFs
fix a bug in UnderfsUtilTest in excluding prefixes
fix a bug in TachyonFS in catching FileDoesNotExistException
Improved getClientFileInfo, getRawTableInfo, getFilesInfo, and ls.

They use the new InodeFolder structure better and are somewhat more
efficient.
add comments to Tachyon.ls() method
Merge pull request #181 from Du-Li/master

more tests on UnderfsUtil.loadUnderFs and bug fixing
fix tachyon.command.Utils.validatePath: use CommonUtils.concat, API documentation
add unit tests for tachyon.command.Utils
rename UtilsTest from TFsShellUtilsTest, couple minor style fixes
Merge pull request #187 from Du-Li/cmdutils

use concat in validatePath, add unit tests and API documentation
format
change pinlist and whitelist separator from semicolon to comma
Added mRawTables check back in
Merge pull request #189 from Du-Li/pinwhilelistseparator

change pinlist and whitelist separator from semicolon to comma
Added mRawTables check to _getClientRawTableInfo

This way it's called by all versions of getClientRawTableInfo.
Removed null check for getPath

It never actually returns null
Merge pull request #183 from manugoyal/more-method-improvements

Improved getClientFileInfo, getRawTableInfo, getFilesInfo, and ls.