Type and naming cleanup

Do not use Hi prefic for things that shouldn't be visible to outside code

include/hitypes.h

@@ -0,0 +1,9 @@
+#ifndef HITYPES_H_
+#define HITYPES_H_
+
+typedef enum { HI_FAIL = 0, HI_OK } HiResult;
+
+#define HIOK(res) ((res) == HI_OK)
+
+
+#endif // HITYPES_H_