wireshark/: Replace ancient dissector with a new one written in Lua.

wireshark/: Replace ancient dissector with a new one written in Lua.

This is mostly a good thing.

  + It work with both Wireshark 1.11 and 2.  The old C code would have
    to choose between the two, and I couldn't easily tell how shiny a
    version of Wireshark I'd be pinning my colours to.

  + It actually dissects the TrIPE protocol as it currently is,
    including all of the group element encodings and bulk crypto
    transforms.

  + It'll be relatively easy to /keep/ the new dissector up-to-date
    relative to protocol changes.

  - It won't run as quickly -- but Lua has a reputation for being quite
    quick, and I'm not expecting to stress it very much.

In theory, I'd be able to put this in an architecture-independent
package, which would greatly shorten cross-build times.  Alas, the
plugin directory encodes the architecture name, so it'll have to be
built separately for each architecture anyway.

Lots of changes:

  * Eliminate the old `packet-tripe.c' dissector.  Add the new one.  Get
    the build system to install it in the right place.

  * Include a (rather shoddy) script for running `tripe' and capturing
    the conversation with `tshark', so I can test the dissector against
    it; and some small example captures.  This might even turn into a
    proper test at some point, but for now it's just something I can do
    by hand.

  * Hack the `configure' script not to need all of the C compile-time
    machinery for building Wireshark plugins.