Updated developer guide

Gao Kai <gaok12@...>

Hi all,

I have updated the developer guide wiki page for ALTO[0], it's still in progress but I think we can still benefit from your feedbacks.  In this update, some out-dated contents are removed from the page and I also did a little tweak on the whole structure.  It would be great if someone can take a look and see if there is anything that is missing or needs clarification.

Your thoughts and suggestions are highly appreciated!


[0] https://wiki.opendaylight.org/view/ALTO:Beryllium_Developer_Guide