Parallel version of DockIt

• Master program reads a single CEX input stream and starts up multiple DockIt executables.
• Each child gets it's CEX input stream from the master using PVM for transport and sends it's output CEX stream back to the master.
• The master collates the results from the children into a single output stream.
• The input and output streams from the master are the same as from a single DockIt executable run. The DockIt children don't know they are running in parallel since they read and write a CEX stream as always.