A simple Evolution run and move between all views means creation of
more than 100 GSettings objects, with only a bit more than 10 schemas.
Reusing the objects should have a positive impact on a performance too.
audio-inline, itip-formatter, prefer-plain, tnef-attachments
and vcard-inline plugins were converted to modules so that they
can fit into concept of the new formatter.
Every module still installs .eplug file, because there is no
suitable API at the moment to register plugins to the plugins dialog
and to extend the Preferences dialog.
