Ahaggar: just use the __lookup_key() for function names lookup

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Ahaggar: improve the match function name logic

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Ahaggar: make the output_handler() pointer able to take two parameters

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Ahaggar: improve the match_output() function

* Change its name
* Make it able to receive two parameters

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>