[AgileWiki] LedgerEntries table

[Bill la F. <bil...@su...>]

DescriptorUnitDescriptorUnit and TableDescriptorUnitDescriptorUnit now 
both have a LedgerEntries table, though other descriptor units can also 
have such a table as needed. This table describes the LEnts of a Rolon 
much as the Columns table describes the LEnts in the rows of a table.