fix: Makefile: add lua include dirs for freebsd

Quick bugfix patch for 0.2.0, fixing some urgent issues that were ove…

…rlooked.

- Bump version (`huxd -V` still returned "0.1.0"!)
- Fixed compile warnings on 32-bit platforms.
- Made config parsing a bit more robust (errors are now properly given when an invalid color is passed).

Well! After some time away I was again able to focus on huxdemp.

Most notably, the tool's abbreviation was renamed (`hxd` ⇒ `huxd`) to avoid
naming clashes with HxD, a Windows hex editing tool that's been around longer
then huxdemp.  (Thanks to M. Hörz, HxD's author, for letting me know.)

A bunch of new features have also been added, making huxdemp a more attractive
alternative to existing tools.

- The *-s* flag was added, which specifies an offset to read the input from.
- The *-n* flag was added, which specifies a maximum number of bytes to be read
  from the input.
- The *-P* flag and an auto-paging feature was added. huxdemp will now
  automatically pipe long outputs to *less*(1) (unless `-P never` is passed).
- Most significantly, the `HUXD_COLORS` environment variable was added, which
  now allows the colors used to be modified at runtime (see the manpage for
  further details).

- Fix invalid escape sequences being emitted, which broke huxdemp completely on
  non-xterm terminals.
- Fix out of range error when `-c` flag is on and characters above 0x7F are
  encountered. (Thanks to @skeeto!)
- Unu, the tool used to generate some source files from literate sources, now
  emits #line directives. This means that crash info (from valgrind or gdb)
  will now use the line numbers of the literate source files, not the generated
  files. This makes debugging a ton easier.

Next up: a plugin system!

README.md: write