Made DBLog final.

Also took out a couple of no-longer-needed casts and cleaned
up a couple of capitalized <p>s in javadoc method headers.
Finalized a bunch of DBObject methods

These methods were never intended to be modified in DBEditObject or
subclasses, and would make no sense to override.

This just makes things a bit neater.
Elaborated method header for DBObject.lookupLabel()
Cleaned up some InvidDBField test code

Let's skip using DBObject's overridable lookupLabel() when reporting
on objects that failed the symmetry test.
Whitespace, comments in gasharl schema classes
Finalized a bunch of Ganymede server classes

Just for sanity's sake, and to make the intended usage clearer.