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.
Namely "Use the same fonts as other applications", "Standard Font",
"Fixed Width Font", "Highlight quotations with color", "Automatically
insert emoticon images" and "Check spelling while I type". Also remove
unneded properties from EWebView.
