Reorganize the source tree.

* Documentation is now in "docs".
 * Source code is now in "src".
 * Misc. fixes here and there so that everything still works.

I think I got everything in this commit, but I only tested this
on Linux (Make) and Windows (CMake), so I might've messed
something up on other platforms...

src/stab.h

@@ -0,0 +1,17 @@
+#ifndef __GNU_STAB__
+
+/* Indicate the GNU stab.h is in use.  */
+
+#define __GNU_STAB__
+
+#define __define_stab(NAME, CODE, STRING) NAME=CODE,
+
+enum __stab_debug_code
+{
+#include "stab.def"
+LAST_UNUSED_STAB_CODE
+};
+
+#undef __define_stab
+
+#endif /* __GNU_STAB_ */