fix for warnings from Sparse static source code checker, mostly BKE/BLI and python functions.

- use NULL rather then 0 where possible (makes code & function calls more readable IMHO).
- set static variables and functions (exposed some unused vars/funcs).
- use func(void) rather then func() for definitions.

source/blender/python/intern/bpy_app.c

@@ -64,7 +64,7 @@ static PyStructSequence_Field app_info_fields[] = {
 	{(char *)"build_cxxflags", (char *)"C++ compiler flags"},
 	{(char *)"build_linkflags", (char *)"Binary linking flags"},
 	{(char *)"build_system", (char *)"Build system used"},
-	{0}
+	{NULL}
 };
 
 static PyStructSequence_Desc app_info_desc = {
@@ -192,7 +192,7 @@ static PyObject *bpy_app_driver_dict_get(PyObject *UNUSED(self), void *UNUSED(cl
 }
 
 
-PyGetSetDef bpy_app_getsets[]= {
+static PyGetSetDef bpy_app_getsets[]= {
 	{(char *)"debug", bpy_app_debug_get, bpy_app_debug_set, (char *)"Boolean, set when blender is running in debug mode (started with -d)", NULL},
 	{(char *)"debug_value", bpy_app_debug_value_get, bpy_app_debug_value_set, (char *)"Int, number which can be set to non-zero values for testing purposes.", NULL},
 	{(char *)"tempdir", bpy_app_tempdir_get, NULL, (char *)"String, the temp directory used by blender (read-only)", NULL},