Disassembled courses, added DLpacker, and disassembled packed DLs (#290)

* Disassembled all courses; packed DLs and course data.

* Added displaylist packer

* Minor documentation and naming

include/course.h

@@ -0,0 +1,17 @@
+#ifndef COURSE_H
+#define COURSE_H
+
+#include <ultra64.h>
+#include <macros.h>
+
+/**
+ * @file Include for course gfx.inc.c.
+*/
+
+// This could be *func(arg) instead.
+struct CourseAddrUnkStruct {
+    uintptr_t addr;
+    s32 value;
+};
+
+#endif // COURSE_H