PyAPI: Skip user scripts w/ factory-startup

Adds bpy.app.factory_startup,
used to check if user scripts should be loaded.

source/blender/python/intern/bpy_app.c

@@ -89,6 +89,7 @@ static PyStructSequence_Field app_info_fields[] = {
 	{(char *)"version_cycle", (char *)"The release status of this build alpha/beta/rc/release"},
 	{(char *)"binary_path", (char *)"The location of blenders executable, useful for utilities that spawn new instances"},
 	{(char *)"background", (char *)"Boolean, True when blender is running without a user interface (started with -b)"},
+	{(char *)"factory_startup", (char *)"Boolean, True when blender is running with --factory-startup)"},
 
 	/* buildinfo */
 	{(char *)"build_date", (char *)"The date this blender instance was built"},
@@ -165,6 +166,7 @@ static PyObject *make_app_info(void)
 	SetStrItem(STRINGIFY(BLENDER_VERSION_CYCLE));
 	SetStrItem(BKE_appdir_program_path());
 	SetObjItem(PyBool_FromLong(G.background));
+	SetObjItem(PyBool_FromLong(G.factory_startup));
 
 	/* build info, use bytes since we can't assume _any_ encoding:
 	 * see patch [#30154] for issue */