Test suite re-organization

With the new structure, we now have four subdirectories right under resources: Regression, Failed, Future and Datasources.  Each test suite will have an entry in each of the four subdirectories, based on the semantics given away by the directory names.  Datasources contains shared data source files across all instances of the same suite under each of the first three directories, and this is realized by way of the datasources block in the json test definition files.

The join test suite has been completed as a reference.  Its tests have been executed to have it confirmed that the new structure works under the current test framework implementation.