introduce modules function table and convenience macro to implement modules

[Alexander Sack]

first step towards lp:692327 - "export plugin/module headers and stable api" is to make a proper function table etc. out of the current modules/plugin API.

1. wrap the current _ntrack_* funcs from ntrackarchapi.h into a function table.
2. declare a struct that allows module meta info definition to include:
   - shortname
   - longname
   - function table
3. define a macro NTRACK_MODULE_DEFINE that makes a meta info definition given the parameters from 2. as arguments.
4. move ntrack-libnl.c to use that API

[Alexander Sack (asac)]

------------------------------------------------------------
revno: 268
fixes bug(s): https://launchpad.net/bugs/694477
committer: Alexander Sack <email address hidden>
branch nick: ntrack
timestamp: Sun 2010-12-26 14:22:32 +0100
message:
  modules: move ntrack-libnl.c to new plugin API - lp:694477
------------------------------------------------------------
revno: 267
fixes bug(s): https://launchpad.net/bugs/694477
committer: Alexander Sack <email address hidden>
branch nick: ntrack
timestamp: Sun 2010-12-26 14:20:55 +0100
message:
  common: factor module plugin API into a func table and intro macro NTRACK_MODULE_DEFINE - lp:694477
------------------------------------------------------------

[Alexander Sack (asac)]

012 is released, fixing this bug: https://launchpad.net/ntrack/main/012