Rename machine_(u)int_t to mp_(u)int_t.

See discussion in issue #50.
diff --git a/py/obj.c b/py/obj.c
index 3077fd2..cfebbf3 100644
--- a/py/obj.c
+++ b/py/obj.c
@@ -83,7 +83,7 @@
 // helper function to print an exception with traceback
 void mp_obj_print_exception(mp_obj_t exc) {
     if (mp_obj_is_exception_instance(exc)) {
-        machine_uint_t n, *values;
+        mp_uint_t n, *values;
         mp_obj_exception_get_traceback(exc, &n, &values);
         if (n > 0) {
             assert(n % 3 == 0);
@@ -145,7 +145,7 @@
     return mp_obj_get_type(o_in)->call != NULL;
 }
 
-machine_int_t mp_obj_hash(mp_obj_t o_in) {
+mp_int_t mp_obj_hash(mp_obj_t o_in) {
     if (o_in == mp_const_false) {
         return 0; // needs to hash to same as the integer 0, since False==0
     } else if (o_in == mp_const_true) {
@@ -155,13 +155,13 @@
     } else if (MP_OBJ_IS_STR(o_in) || MP_OBJ_IS_TYPE(o_in, &mp_type_bytes)) {
         return mp_obj_str_get_hash(o_in);
     } else if (MP_OBJ_IS_TYPE(o_in, &mp_type_NoneType)) {
-        return (machine_int_t)o_in;
+        return (mp_int_t)o_in;
     } else if (MP_OBJ_IS_TYPE(o_in, &mp_type_fun_native) || MP_OBJ_IS_TYPE(o_in, &mp_type_fun_bc)) {
-        return (machine_int_t)o_in;
+        return (mp_int_t)o_in;
     } else if (MP_OBJ_IS_TYPE(o_in, &mp_type_tuple)) {
         return mp_obj_tuple_hash(o_in);
     } else if (MP_OBJ_IS_TYPE(o_in, &mp_type_type)) {
-        return (machine_int_t)o_in;
+        return (mp_int_t)o_in;
 
     // TODO hash class and instances
     // TODO delegate to __hash__ method if it exists
@@ -225,7 +225,7 @@
     return false;
 }
 
-machine_int_t mp_obj_get_int(mp_const_obj_t arg) {
+mp_int_t mp_obj_get_int(mp_const_obj_t arg) {
     // This function essentially performs implicit type conversion to int
     // Note that Python does NOT provide implicit type conversion from
     // float to int in the core expression language, try some_list[1.0].
@@ -244,8 +244,8 @@
 
 // returns false if arg is not of integral type
 // returns true and sets *value if it is of integral type
-// can throw OverflowError if arg is of integral type, but doesn't fit in a machine_int_t
-bool mp_obj_get_int_maybe(mp_const_obj_t arg, machine_int_t *value) {
+// can throw OverflowError if arg is of integral type, but doesn't fit in a mp_int_t
+bool mp_obj_get_int_maybe(mp_const_obj_t arg, mp_int_t *value) {
     if (arg == mp_const_false) {
         *value = 0;
     } else if (arg == mp_const_true) {
@@ -330,8 +330,8 @@
 }
 
 // is_slice determines whether the index is a slice index
-uint mp_get_index(const mp_obj_type_t *type, machine_uint_t len, mp_obj_t index, bool is_slice) {
-    machine_int_t i;
+uint mp_get_index(const mp_obj_type_t *type, mp_uint_t len, mp_obj_t index, bool is_slice) {
+    mp_int_t i;
     if (MP_OBJ_IS_SMALL_INT(index)) {
         i = MP_OBJ_SMALL_INT_VALUE(index);
     } else if (!mp_obj_get_int_maybe(index, &i)) {
@@ -363,7 +363,7 @@
         MP_OBJ_IS_STR(o_in) ||
 #endif
         MP_OBJ_IS_TYPE(o_in, &mp_type_bytes)) {
-        return MP_OBJ_NEW_SMALL_INT((machine_int_t)mp_obj_str_get_len(o_in));
+        return MP_OBJ_NEW_SMALL_INT((mp_int_t)mp_obj_str_get_len(o_in));
     } else {
         mp_obj_type_t *type = mp_obj_get_type(o_in);
         if (type->unary_op != NULL) {