- deprecate:
        - gnt_styles_get_keyremaps
        - gnt_style_read_actions
        - gnt_widget_expose
        - gnt_widget_queue_update
        - gnt_ws_widget_hide/show
 either remove them altogether, or move them in some internal header file.
- move some of the functions from gnt.h to more approp. places. eg. in gntbox.h, gntwidget.h etc.
- use _set_column_ everywhere, instead of _set_col_ in some places
- use some consistent naming for GntXXXFlag and GntXXXFlags.
- rename the _menuitem_ functions to _menu_item_, or rename GntMenuItem to GntMenuitem
- _ref and _unref items/widgets when doing add_item/add_widget on GntMenu/GntBox