----------------
* Made the executor fail gracefully if the content being acted upon is not
adaptable to the replacer interface.
[optilude]
* Made the default replacer adapt any Dublin Core-capable content, avoiding
an unnecessary dependency on Archetypes.
[optilude]
* Made the default IMailModel implementation more re-usable.
[optildue]
* Updated documentation and interface specifications.
[optilude]
* Fixes actions/configure.zcml in order to play nice with GenericSetup