[gnome-db] GdaColumn as a GObject

[Murray Cumming <murrayc murrayc com>]

In libgda HEAD, GdaColumn was recently changed to be a GObject, instead
of being a copyable boxed type (struct).

This makes ownership a little less obvious. For instance, may we ever
use the gda_column_set_*() methods on a GdaColumn that we get from
gda_data_model_describe_column() before passing it to
gda_data_model_append_column()? I guess not, because we are using the
same instance.

I guess we need to always create a new GdaColumn before using the set
methods, but it seems worth asking/clarifying.

If we could keep the copy function (removed when it was changed to a
GObject), some things would be easier for me.

-- 
Murray Cumming
murrayc murrayc com
www.murrayc.com
www.openismus.com