layers: Add default layer error message config

Allows layers to output error messages even if no vk_layer_settings.txt
config file is present. Sets defaults to LOG_MSG, error, stdout.
A layer settings file will override any default values. If no settings
file is present and an app creates a debug callback, the default
callbacks will be removed and unregistered.

Change-Id: I49f37189665816df58c258b9e9629f2bf76751c8
diff --git a/vk-layer-generate.py b/vk-layer-generate.py
index 0ec0bc0..a645f4b 100755
--- a/vk-layer-generate.py
+++ b/vk-layer-generate.py
@@ -302,6 +302,7 @@
             r_body.append('    if (VK_SUCCESS == result) {')
             r_body.append('        layer_data *my_data = get_my_data_ptr(get_dispatch_key(instance), layer_data_map);')
             r_body.append('        result = layer_create_msg_callback(my_data->report_data,')
+            r_body.append('                                           false,')
             r_body.append('                                           pCreateInfo,')
             r_body.append('                                           pAllocator,')
             r_body.append('                                           pCallback);')
@@ -311,7 +312,7 @@
             r_body.append('    VkResult result = instance_dispatch_table(instance)->CreateDebugReportCallbackEXT(instance, pCreateInfo, pAllocator, pCallback);')
             r_body.append('    if (VK_SUCCESS == result) {')
             r_body.append('        layer_data *my_data = get_my_data_ptr(get_dispatch_key(instance), layer_data_map);')
-            r_body.append('        result = layer_create_msg_callback(my_data->report_data, pCreateInfo, pAllocator, pCallback);')
+            r_body.append('        result = layer_create_msg_callback(my_data->report_data, false, pCreateInfo, pAllocator, pCallback);')
             r_body.append('    }')
             r_body.append('    return result;')
         r_body.append('}')