develop/libraries/box_lib: Post-SVN tidy

- Move source code from `trunk` into program root directory.
- Update build files and ASM include paths.
- Note: Line endings standardised from `CRLF` > `LF`, so best to view diffs with whitespace changes hidden.

programs/develop/libraries/box_lib/Tupfile.lua

@@ -0,0 +1,2 @@
+if tup.getconfig("NO_FASM") ~= "" then return end
+tup.rule("box_lib.asm", "fasm %f %o " .. tup.getconfig("KPACK_CMD"), "box_lib.obj")