lib/display_info && background:sync from startdde/dialogUI/lib

main changes:

1.sync lib/display_info && back from startdde to prepare handling
mult-screen
main changed:
a.change update_display_info --> update_primary_info
b.move app/launcher/bg.c to lib/background.c
  ------  move setup_background to lib/background.c
  ------  because lib/display_info.c should use the function
c.add more mult-monitors handling function in display_info.c
  for app to use

2.update launcher src --- test ok
    --- update_display_info -->  update_primary_info
    --- delete bg.c bg.h
    --- add "_DDE_BACKGROUND_PIXMAP_BLURRED" in setup_background

3.update dock src  --- test ok
    --- update_display_info -->  update_primary_info

4.update desktop src --- test ok
    --- update_display_info -->  update_primary_info
    --- delete some useless function replaced by display_info.c function
        widget_move_by_rect(container,rect_primary);

5.update zone src --- test ok
    --- update_display_info -->  update_primary_info
    --- add "monitors-changed" signal callback

6.update osd src --- test ok
    --- delete only_show_in_primary
    and osd will show in the screen which it has focus on

7.update lowpower src --- test ok
    --- only show image in primary screen
    --- add "monitors-changed" signal callback

8.update guide src --- test ok
    --- update_display_info -->  update_primary_info
    --- add "monitors-changed" signal callback

9.TODO:
  see details in CL:
    http://121.40.93.113:8080/827

Change-Id: I09b461874ad5f03eb40a67c07721d0a769684e94