Stage 1 of rename

TODO: re-enable glave build, advance API for glave

v2: get rid of outdated code in tri introduced by rebase
    rename wsi_null.c (olv)
diff --git a/icd/nulldrv/nulldrv.h b/icd/nulldrv/nulldrv.h
index 28d73ba..22af6c6 100644
--- a/icd/nulldrv/nulldrv.h
+++ b/icd/nulldrv/nulldrv.h
@@ -1,5 +1,5 @@
 /*
- * XGL
+ * Vulkan
  *
  * Copyright (C) 2014 LunarG, Inc.
  *
@@ -30,14 +30,14 @@
 #include <string.h>
 #include <assert.h>
 
-#include <xgl.h>
-#include <xglDbg.h>
-#include <xglIcd.h>
+#include <vulkan.h>
+#include <vkDbg.h>
+#include <vkIcd.h>
 
 #if defined(PLATFORM_LINUX)
-#include <xglWsiX11Ext.h>
+#include <vkWsiX11Ext.h>
 #else
-#include <xglWsiWinExt.h>
+#include <vkWsiWinExt.h>
 #endif
 
 #include "icd.h"
@@ -48,7 +48,7 @@
 struct nulldrv_base {
     void *loader_data;
     uint32_t magic;
-    XGL_RESULT (*get_info)(struct nulldrv_base *base, int type1,
+    VK_RESULT (*get_info)(struct nulldrv_base *base, int type1,
                            size_t *size, void *data);
 };
 
@@ -100,12 +100,12 @@
 
 struct nulldrv_img {
     struct nulldrv_obj obj;
-    XGL_IMAGE_TYPE type;
+    VK_IMAGE_TYPE type;
     int32_t depth;
     uint32_t mip_levels;
     uint32_t array_size;
-    XGL_FLAGS usage;
-    XGL_IMAGE_FORMAT_CLASS format_class;
+    VK_FLAGS usage;
+    VK_IMAGE_FORMAT_CLASS format_class;
     uint32_t samples;
     size_t total_size;
 };
@@ -113,7 +113,7 @@
 struct nulldrv_mem {
     struct nulldrv_base base;
     struct nulldrv_bo *bo;
-    XGL_GPU_SIZE size;
+    VK_GPU_SIZE size;
 };
 
 struct nulldrv_ds_view {
@@ -135,8 +135,8 @@
 
 struct nulldrv_buf {
     struct nulldrv_obj obj;
-    XGL_GPU_SIZE size;
-    XGL_FLAGS usage;
+    VK_GPU_SIZE size;
+    VK_FLAGS usage;
 };
 
 struct nulldrv_desc_layout {