Merge branch '2919_widget_focus_refactoring'

Merge branch '2919_widget_focus_refactoring'

* 2919_widget_focus_refactoring:
  Reimplement widget focus/selection.
  (dlg_set_bottom_widget): rename to widget_set_bottom.
  (dlg_select_widget): rename to widget_select.
  Rename WDialog APIs:
  Refactoring of change of current widget.
  WMenuBar: remove WMenuBar::is_active. Use WST_FOCUSED instead.
  WInput: avoid double draw on resize.
  Menu: avoid double draw on resize.
  (widget_set_size): send MSG_DRAW after MSG_RESIZE.
  Refactoring of widget drawing to avoid multiple widget redraw.
  WView: remove WView::active. Use WST_FOCUSED instead.
  WTree: remove WTree:active. Use WST_FOCUSED instead.
  WButton: remove WButton::selected. Use WST_FOCUSED instead.
  WListbox: remove WListbox::focused. Use WST_FOCUSED instead.
  WST_FOCUSED: add new state and handle it.
  (menubar_callback): refactoring of menu draw after get focus and resize.
  (widget_set_state): return cb_ret_t instead of gboolean.
  Don't focus widget that doesn't have the WOP_SELECTABLE option.
  Use WOP_SELECTABLE option in menu.
  Ticket #2919: refactoring of focus/unfocus of widgets.