* Modify temporary rpath for testing in java example scripts.
* Update URL in source file Copyright headers for web copy of COPYING
file - src and test directories.
* Detect coredumps, and avoid printing a warning when creating a directory that already exists
* Retrieve the actual datatype object correctly, in the face of possible pass-through VOL connectors
* Detect more core dumps, and tiny formatting cleanup
* Revert error status checks for mirror VFD test script
1. restored the datatype, dataspace, and LCPL of the dataset for VOL connector back to the properties.
2. splitted external.c and vds.c because they called HDsetenv in the program, instead using shell scripts to set the environment variables.
3. changed H5CX_get_vds_prefix and H5CX_get_ext_file_prefix to use H5P_peek instead of H5P_get.
