Trim HarvestJobManager related documentation on the wiki

As part of the reading of the configuration and system manual during release test I have stumpled across some Harvesting related documentation which should be updated to better reflect the recent updates made to the HarvestJobManager related code.
Because it is very difficult to keep the mostly redundant information in the Javadoc System manual installation manual and Configuration manuel updated and consistent we should trim the information by moving as much information as possible to Javadoc (including package level documentation) and use hyperlinking to refer from the wiki based top level information to detailed information found in the Javadoc (or perhaps even the source code browsable through Fisheye)