Provide access to all local sectors for one central sector
Convert to a new object system, change documentation method

Rather than the mess of different initialization methods we had before,
now there are just two. object_new, and object_init.

I've also changed the way I document functions. Rather than listing every
single parameter, which is mostly useless and just serves to discourage
programmers from writing good comments, we just document the non-obvious
parameters and return values. I also no longer include the function name
in the documentation comment (it's listed just a few lines down in the
definition anyway)