Use mc_event engine to handle focus/unfocus events.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
New group API to select/unselect widget.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Modify update_cursor API to support groups.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Small refactoring of dialog size and position set/change.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Reimplement set widget size to support groups.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Reimplement dialog validation: use separate function.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Reimplement dialog idle state: use separate function.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Create WBackground widget.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Create WFrame widget.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Use WBackground and WFrame in dialogs.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Move winch_pending member from WDialog to WGroup.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Rename widget_redraw() to widget_draw().

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Modify widget draw to support groups.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Rename mouse_h to mouse_handler_t.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>