[TACHYON-65] Fix the listFiles method

[TACHYON-65] the ListFiles(path,recursive) function of
tachyon.master.MasterInfo class does not work well
switch to CLASSPATH internally so TACHYON_CLASSPATH is optional.  Fixed typo in stop script.  Find openjdk if oracle not found
Add the unit test for [TACHYON-65]
Merge pull request #350 from PasaLab/TACHYON-65

[TACHYON-65] Fix the listFiles method in tachyon.master.MasterInfo
Merge pull request #353 from dcapwell/shell-fix

Changes to shell scripts