Results of the discussion about parameters removal

[Joel Peshkin]

We should be able to get rid of shadowdbhost, shadowdbsock, shadowdbport.

   shadowdb can be redefined to be the DSN of the database.  So, that can be
    myshadowdb
    database=myshadowdb
    database=myshadowdb;host=myshadowhost
    database=myshadowdb;host=myshadowhost;port=8900
    database=myshadowdb;mysql_socket=/var/mysql.sock
Oracle and Pg seem to support similar syntaxes.

Also, as we move various *group items to groups, we risk cluttering up 
the groups UI just as badly.  We should consider reserving the group 
names, but not pre-creating them so, if the group isn't defined, the 
feature is disabled.