Layers: They now compile on Windows.

Added missing vk funcs to basic and screenshot
Changed several funcs in mem_tracker to return void
Loader cmake file was generating .def file on linux, removed it
Fixed missing entry points in layers generated via python
diff --git a/layers/basic.cpp b/layers/basic.cpp
index aec3ea4..d1e7805 100644
--- a/layers/basic.cpp
+++ b/layers/basic.cpp
@@ -33,6 +33,15 @@
 // being used:
 #include "vk_loader_platform.h"
 
+static const VkLayerProperties globalLayerProps[] = {
+    {
+        "Basic",
+        VK_API_VERSION,                 // specVersion
+        VK_MAKE_VERSION(0, 1, 0),       // implVersion
+        "layer: Basic",
+    }
+};
+
 
 VK_LAYER_EXPORT VkResult VKAPI vkLayerExtension1(VkDevice device)
 {
@@ -175,3 +184,13 @@
         return NULL;
     return instance_dispatch_table(instance)->GetInstanceProcAddr(instance, pName);
 }
+
+VK_LAYER_EXPORT VkResult VKAPI vkGetGlobalExtensionProperties(const char *pLayerName, uint32_t *pCount,  VkExtensionProperties* pProperties)
+{
+    return util_GetExtensionProperties(0, NULL, pCount, pProperties);
+}
+
+VK_LAYER_EXPORT VkResult VKAPI vkGetGlobalLayerProperties(uint32_t *pCount,  VkLayerProperties* pProperties)
+{
+    return util_GetLayerProperties(ARRAY_SIZE(globalLayerProps), globalLayerProps, pCount, pProperties);
+}
diff --git a/layers/mem_tracker.cpp b/layers/mem_tracker.cpp
index e6f23f9..3dc7fb8 100644
--- a/layers/mem_tracker.cpp
+++ b/layers/mem_tracker.cpp
@@ -254,7 +254,7 @@
 //  Verify that (actual & desired) flags != 0 or,
 //   if strict is true, verify that (actual & desired) flags == desired
 //  In case of error, report it via dbg callbacks
-static bool32_t validate_usage_flags(void* disp_obj, VkFlags actual, VkFlags desired,
+static void validate_usage_flags(void* disp_obj, VkFlags actual, VkFlags desired,
                                      bool32_t strict, VkObject obj, VkObjectType obj_type,
                                      char const* ty_str, char const* func_name, char const* usage_str)
 {
@@ -272,7 +272,7 @@
 // Helper function to validate usage flags for images
 // Pulls image info and then sends actual vs. desired usage off to helper above where
 //  an error will be flagged if usage is not correct
-static bool32_t validate_image_usage_flags(void* disp_obj, VkImage image, VkFlags desired, bool32_t strict,
+static void validate_image_usage_flags(void* disp_obj, VkImage image, VkFlags desired, bool32_t strict,
                                            char const* func_name, char const* usage_string)
 {
     MT_OBJ_INFO* pInfo = get_object_info(image);
@@ -284,7 +284,7 @@
 // Helper function to validate usage flags for buffers
 // Pulls buffer info and then sends actual vs. desired usage off to helper above where
 //  an error will be flagged if usage is not correct
-static bool32_t validate_buffer_usage_flags(void* disp_obj, VkBuffer buffer, VkFlags desired, bool32_t strict,
+static void validate_buffer_usage_flags(void* disp_obj, VkBuffer buffer, VkFlags desired, bool32_t strict,
                                             char const* func_name, char const* usage_string)
 {
     MT_OBJ_INFO* pInfo = get_object_info(buffer);
diff --git a/layers/screenshot.cpp b/layers/screenshot.cpp
index 5b8c098..69b99f3 100644
--- a/layers/screenshot.cpp
+++ b/layers/screenshot.cpp
@@ -554,3 +554,25 @@
         return NULL;
     return pDisp->GetDeviceProcAddr(dev, funcName);
 }
+
+
+VK_LAYER_EXPORT void* VKAPI vkGetInstanceProcAddr(VkInstance instance, const char* funcName)
+{
+    return NULL;
+#if 0
+    if (instance == VK_NULL_HANDLE) {
+        return NULL;
+    }
+
+    /* loader uses this to force layer initialization; instance object is wrapped */
+    if (!strcmp("vkGetInstanceProcAddr", funcName)) {
+        initInstanceTable((const VkBaseLayerObject *) instance);
+        return (void *) vkGetInstanceProcAddr;
+    }
+
+    VkLayerInstanceDispatchTable* pTable = instance_dispatch_table(instance);
+    if (pTable->GetInstanceProcAddr == NULL)
+        return NULL;
+    return pTable->GetInstanceProcAddr(instance, funcName);
+#endif
+}