Improved delete method

Modified it to use the new InodeFolder structure better. Also made the
edit log call to delete use a non-logging version. Also put
traverseToInode in alphabetical order.
Removed the extra delete methods

They weren't necessary
Small fixes to _delete
Modified delInodes to use ArrayList rather than HashSet
Moved checkpoint deletion before InodeFolder deletion
Removed succeed variable in _delete
Merge pull request #190 from manugoyal/improved-delete-2

Improved delete 2