Implementing the replacement of the filtermap

A system based on an attribute, and a locator for the filter to results
mapping based on attribute reflection of all the classes implementing
IFilterResult
First outlines for MEF implementation

MEF will be used extensively throughout the project.  First and foremost
for the plugin system but also  for on the fly refreshing of filter
rules, runtime added plugins and other cool stuff.
Added (seemingly removed) reference to mef
Merge branch 'master' into MEF-implementation
Rewritten FilterMap and in the process implemented the first MEF export/import relationship.