py: Change uint to mp_uint_t in runtime.h, stackctrl.h, binary.h.
Part of code cleanup, working towards resolving issue #50.
diff --git a/py/objstrunicode.c b/py/objstrunicode.c
index 853e3dc..8231eb9 100644
--- a/py/objstrunicode.c
+++ b/py/objstrunicode.c
@@ -154,7 +154,7 @@
// Convert an index into a pointer to its lead byte. Out of bounds indexing will raise IndexError or
// be capped to the first/last character of the string, depending on is_slice.
-const byte *str_index_to_ptr(const mp_obj_type_t *type, const byte *self_data, uint self_len,
+const byte *str_index_to_ptr(const mp_obj_type_t *type, const byte *self_data, mp_uint_t self_len,
mp_obj_t index, bool is_slice) {
mp_int_t i;
// Copied from mp_get_index; I don't want bounds checking, just give me