[ECOS] [porting] Porting guide updated

[Jesper Skov <jskov at redhat dot com>]

Greetings, eCosmonauts :)

I've just checked in a fairly big update of the porting guide. The
platform porting information is nearly complete now - at least as
complete as it will be without some feedback.

 http://sources.redhat.com/ecos/docs-latest/porting/

I still need to add something about variant and architecture porting,
as well as improving some of the short HAL introductory material. That
will happen in time.  

Please send feedback/comments to the list, using [porting] as a
subject prefix.

Thanks,
Jesper