intel: overhaul the internal WSI interface

The goal is to hide X11 details from the rest of the driver and move closer to
upstream WSI extensions that are still in development.  As a result hiding X11
details, ENABLE_WSI_X11 is unnecessary and is removed.

To move closer to upstream WSI extensions, intel_gpu_associate_x11() is
removed.  The X11 connection is available much later in upstream WSI
extensions.

There is also a bug fix.  When a fence is used like this

  xglQueuePresent(..., fence);
  xglQueueSubmit(..., fence);
  xglWaitForFences(..., &fence);

it will (correctly) wait for the present to finish before waiting for the
command buffer.
diff --git a/icd/intel/wsi_null.c b/icd/intel/wsi_null.c
new file mode 100644
index 0000000..156a0b6
--- /dev/null
+++ b/icd/intel/wsi_null.c
@@ -0,0 +1,101 @@
+/*
+ * XGL
+ *
+ * Copyright (C) 2015 LunarG, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ *   Chia-I Wu <olv@lunarg.com>
+ */
+
+#include "wsi.h"
+
+XGL_RESULT intel_wsi_gpu_get_info(struct intel_gpu *gpu,
+                                  XGL_PHYSICAL_GPU_INFO_TYPE type,
+                                  size_t *size, void *data)
+{
+    return XGL_ERROR_INVALID_VALUE;
+}
+
+void intel_wsi_gpu_cleanup(struct intel_gpu *gpu)
+{
+}
+
+XGL_RESULT intel_wsi_img_init(struct intel_img *img)
+{
+    return XGL_SUCCESS;
+}
+
+void intel_wsi_img_cleanup(struct intel_img *img)
+{
+}
+
+XGL_RESULT intel_wsi_fence_init(struct intel_fence *fence)
+{
+    return XGL_SUCCESS;
+}
+
+void intel_wsi_fence_cleanup(struct intel_fence *fence)
+{
+}
+
+void intel_wsi_fence_copy(struct intel_fence *fence,
+                          const struct intel_fence *src)
+{
+}
+
+XGL_RESULT intel_wsi_fence_wait(struct intel_fence *fence,
+                                int64_t timeout_ns)
+{
+    return XGL_SUCCESS;
+}
+
+ICD_EXPORT XGL_RESULT XGLAPI xglWsiX11AssociateConnection(
+    XGL_PHYSICAL_GPU                            gpu_,
+    const XGL_WSI_X11_CONNECTION_INFO*          pConnectionInfo)
+{
+    return XGL_ERROR_UNKNOWN;
+}
+
+ICD_EXPORT XGL_RESULT XGLAPI xglWsiX11GetMSC(
+    XGL_DEVICE                                  device,
+    xcb_window_t                                window,
+    xcb_randr_crtc_t                            crtc,
+    uint64_t  *                                 pMsc)
+{
+    return XGL_ERROR_UNKNOWN;
+}
+
+ICD_EXPORT XGL_RESULT XGLAPI xglWsiX11CreatePresentableImage(
+    XGL_DEVICE                                  device,
+    const XGL_WSI_X11_PRESENTABLE_IMAGE_CREATE_INFO* pCreateInfo,
+    XGL_IMAGE*                                  pImage,
+    XGL_GPU_MEMORY*                             pMem)
+{
+    return XGL_ERROR_UNKNOWN;
+}
+
+ICD_EXPORT XGL_RESULT XGLAPI xglWsiX11QueuePresent(
+    XGL_QUEUE                                   queue_,
+    const XGL_WSI_X11_PRESENT_INFO*             pPresentInfo,
+    XGL_FENCE                                   fence_)
+{
+    return XGL_ERROR_UNKNOWN;
+}