Don't call scan() in loadAnnotations()

Previously, loadAnnotations() were written such a
way that it made it sure that scan() was run
before trying to anchor any annotations.

After removing this feature, now it's the
responsibility of the application code
to call scan() before loadAnnotions().

(Of course this only matters when the
`dontScan` option was given to the
application, because otherwise, we do
a scanning right away in in constructor.)