Fix issue #369 (new hpcclient & hpcserver API)

Fix issue #369 (closed) : Adopting new hpcclient API:

• use kinds of RemotePath (hpcclient-java#24 (moved))
• use the default empty directory (hpcclient-java#29 (closed))
• use the default hpcserver argument (hpcserver#112 (closed))
• relies on hpcserver's simplified remote path (hpcserver#115 (closed))