his protocol realizes following features,
- UI ready
- changing modes; tiling, side by side, full_screen, and random
- Give control a surface; workspace to be controlled by using ivi layout APIs
- Display/undisplay a surface; home contains sevaral workspaces to launch
  application

Signed-off-by: Tarnyko <tarnyko@tarnyko.net>
---

Changes for v2:
 - squash Makefile to this patch

Changes for v3 and v4
  - nothing. Version number aligned to the first patch

Changes for v5:
 - rebase weston v1.5 branch
 - apply review comments from mailing list
The library is used to manage layout of surfaces/layers. Layout change is
triggered by ivi-hmi-controller protocol, ivi-hmi-controller.xml. A reference
how to use the protocol, see hmi-controller-homescreen.

In-Vehicle Infotainment system usually manage properties of surfaces/layers
by only a central component which decide where surfaces/layers shall be. This
reference show examples to implement the central component as a module of
weston.

Default Scene graph of UI is defined in hmi_controller_create. It consists of
- In the bottom, a base layer to group surfaces of background, panel,
  and buttons
- Next, a application layer to show application surfaces.
- Workspace background layer to show a surface of background image.
- Workspace layer to show launcher to launch application with icons. Paths to
  binary and icon are defined in weston.ini. The width of this layer is longer
  than the size of screen because a workspace has several pages and is
  controlled by motion of input.

Signed-off-by: Tarnyko <tarnyko@tarnyko.net>
---

Changes for v2:
 - squash Makefile to this patch

Changes for v3 and v4
 - nothing. Version number aligned to the first patch

Changes for v5:
 - rebase weston v1.5 branch
 - apply review comments from mailing list
This is launched from hmi-controller by launch_hmi_client_process and invoke a
client process.

The basic flow is as followed,
1/ process invoked
2/ read configuration from weston.ini.
3/ draw png file to surface according to configuration of weston.ini
4/ all parts of UI are ready. request "UI_ready" to draw UI.
5/ Enter event loop
6/ If a surface receives touch/pointer event, followings are invoked according
   to type of event and surface
6-1/ If a surface to launch ivi_application receive touch up, it execs
     ivi-application configured in weston.ini.
6-2/ If a surface to switch layout mode receive touch up, it sends a request,
     ivi_hmi_controller_switch_mode, to hmi-controller.
6-3/ If a surface to show workspace having launchers, it sends a request,
     ivi_hmi_controller_home, to hmi-controller.
6-4/ If touch down events happens in workspace,
     ivi_hmi_controller_workspace_control is sent to slide workspace.
     When control finished, event: ivi_hmi_controller_workspace_end_control
     is received.

Signed-off-by: Tarnyko <tarnyko@tarnyko.net>
---

Changes for v2:
 - squash Makefile to this patch

Changes for v3 and v4
 - nothing. Version number aligned to the first patch

Changes for v5:
 - rebase weston v1.5 branch
 - apply review comments from mailing list
Signed-off-by: Tarnyko <tarnyko@tarnyko.net>
---
Changes for v2:
 - squash Makefile to this patch

Changes for v3, v4, and v5:
 - nothing. Version number aligned to the first patch
Signed-off-by: Tarnyko <tarnyko@tarnyko.net>
---

Changes for v2:
 - squash Makefile to this patch

Changes for v3 and v4:
  - nothing. Version number aligned to the first patch

Changes for v5:
  - rebase weston v1.5 branch
Signed-off-by: Tarnyko <tarnyko@tarnyko.net>
---

Changes for v2, v3 and v4:
  - nothing. Version number aligned to the first patch

Changes for v5:
  - rebase weston v1.5 branch
  - remove Macros to enable ivi-application