Add finished code for serializing a directory into the binary

The Perl script generates a table of files and their data that is
compiled into the testing binary, allowing us to serve the HTTP GUI over
the same HTTP server as the RPC.

Thus, we avoid the overhead of installing, configuring, and running a
real HTTP server on the BBB. This is a big usability win, since we can
literally send a staticly-compiled binary for the BBB and say "just run
it", and it will work.