Bump version to 1.29.0
Bump version to 1.29.0

This keeps us in sync with gobject-introspection, which in turn is
trying to keep roughly in sync with glib.

The "1" prefix signals "unstable" still.

https://bugzilla.gnome.org/show_bug.cgi?id=650497

endlessm/gjs,magcius/gjs,magcius/gjs,endlessm/gjs,pixunil/cjs,djdeath/gjs,endlessm/gjs,pixunil/cjs,mtwebster/cjs,pixunil/cjs,pixunil/cjs,djdeath/gjs,djdeath/gjs,endlessm/gjs,magcius/gjs,mtwebster/cjs,djdeath/gjs,djdeath/gjs,magcius/gjs,mtwebster/cjs,pixunil/cjs,mtwebster/cjs,magcius/gjs,mtwebster/cjs,endlessm/gjs