This commit (in theory) only reorganizes code, not change actual functionality.
RegionFactory now uses a distinct Region constructor for each case, which is a bit easier to wrap around.
Note comment at region.cc:276, this case seems pretty weird to me (more hangover?).
git-svn-id: svn://localhost/ardour2/branches/3.0@8320 d708f5d6-7413-0410-9779-e7cbd77b26cf