py: Convert [u]int to mp_[u]int_t where appropriate.
Addressing issue #50.
diff --git a/py/objint.h b/py/objint.h
index 638742a..70d182b 100644
--- a/py/objint.h
+++ b/py/objint.h
@@ -36,9 +36,9 @@
extern const mp_obj_int_t mp_maxsize_obj;
void mp_obj_int_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind);
-char *mp_obj_int_formatted(char **buf, int *buf_size, int *fmt_size, mp_const_obj_t self_in,
+char *mp_obj_int_formatted(char **buf, mp_uint_t *buf_size, mp_uint_t *fmt_size, mp_const_obj_t self_in,
int base, const char *prefix, char base_char, char comma);
-char *mp_obj_int_formatted_impl(char **buf, int *buf_size, int *fmt_size, mp_const_obj_t self_in,
+char *mp_obj_int_formatted_impl(char **buf, mp_uint_t *buf_size, mp_uint_t *fmt_size, mp_const_obj_t self_in,
int base, const char *prefix, char base_char, char comma);
mp_int_t mp_obj_int_hash(mp_obj_t self_in);
bool mp_obj_int_is_positive(mp_obj_t self_in);