Quit adding date to the name of log directory. Now it is always under vlog dir
readClob() and delegateQueryAsync() added
getters are added
TraverserHelperAsync is implemented via extending AbstractTraverseHelper which holds the common methods for TraverseHelper. JsonKeyConstants is introducted to be used as keys in the json. A new method -delegateQueryWithoutResult- to be used for async operation is added
json for async op