Proper support for registering builtin modules in ROM.

Comes with some refactoring of code and renaming of files.  All modules
are now named mod*.[ch].

py/modarray.c

@@ -0,0 +1,25 @@
+#include "misc.h"
+#include "mpconfig.h"
+#include "qstr.h"
+#include "obj.h"
+#include "map.h"
+#include "builtin.h"
+
+STATIC const mp_map_elem_t mp_module_array_globals_table[] = {
+    { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_array) },
+    { MP_OBJ_NEW_QSTR(MP_QSTR_array), (mp_obj_t)&mp_type_array },
+};
+
+STATIC const mp_map_t mp_module_array_globals = {
+    .all_keys_are_qstrs = 1,
+    .table_is_fixed_array = 1,
+    .used = sizeof(mp_module_array_globals_table) / sizeof(mp_map_elem_t),
+    .alloc = sizeof(mp_module_array_globals_table) / sizeof(mp_map_elem_t),
+    .table = (mp_map_elem_t*)mp_module_array_globals_table,
+};
+
+const mp_obj_module_t mp_module_array = {
+    .base = { &mp_type_module },
+    .name = MP_QSTR_array,
+    .globals = (mp_map_t*)&mp_module_array_globals,
+};