Hi Marcel/Johan, 

Attaching a patch for the telephony plugin framework. 
I have added a 'configure' option (--enable-plugin) which compiles all
the plugins (currently only test plugin). Then the specific plugin can
be selected through audio.conf.
Let me know what you think.

Marcel, can you approve and create the plugin files
(audio/hfp_plugin_test.c and audio/hfp_plugin.h)? 

Thanks, 
Alok.