identified more issues with inheritance. mapper inheritance is more closed-minded...

identified more issues with inheritance.  mapper inheritance is more closed-minded about how it creates the join crit
erion as well as the sync rules in inheritance.  syncrules have been tightened up to be smarter about creating a new
SyncRule given lists of tables and a join clause.  properties also checks for relation direction against the "noninherited table" which for the moment makes it a stronger requirement that a relation to a mapper must relate to that mapper's main table, not any tables that it inherits from.