Modifications and objectives of reworked architecture.

Base version : Dumper 0.9.2 

Rework the architecture to enable additional metatype dumpers
to be implemented and registered.

Factor the original Dumper implementation to enable programmatic
invocation independent of the creation of an OFS DumperX
in the zope image.

Add dump option to enable more agressive pruning of metadata
[e.g., don't write title in metadata of a Python script
if that's the only property, it's already encoded
in the object representation]

Provide extensible framework for custom dump options.

Add object loader capability.

[D. Lewis 16-Jul-2006]