resolve UnderFS hostname in loadufs, add methods in tachyon.util.CommonUtils and unit tests
resolve UnderFS hostname before using in loadufs
some minor code style fixes
Improved rename

Made it more thorough and use the new InodeFolder structure.
Removed null check for getPath in rename
Created _rename method, which allows EditLog to replay rename without
logging
Fixed inner _rename method
Added comments for exceptions in _rename
Fixed _rename and added @throws to CommonUtils javadoc
Made rename return a boolean rather than throw exceptions
fix test cases to cover empty and null, and resolveHostName
fix resolveHostNameTest
Merge pull request #188 from Du-Li/resolvehostname

resolve hostname in UnderFS address in loadufs, add unit tests and documentation
Merge pull request #184 from manugoyal/rename-improvements

Improved rename
minor fix to rename edit log
format and make rename return boolean
organize utils.
Fix unit test