noLink -> addLink

Replace the variable "noLink" by "addLink". This saves you the
two seconds for thinking about the multiple negation
`#unless noLink #else ..`. `#if addLink #else ..` is more
readily grasped.
So yes, this is why I am saying that we could simply decide to have dots everywhere. I think all current developers prefer that style (including me). The only reason why we still have without dots is:
* consistency with existing code (we have it this way), but one pull request can fix all of that
* I decided initially for this style because in other projects I had lazy developers who didn't want to do dots, but I see that we here have different view, so I am all for changing it (but then we have to change everywhere)

This change would be best done just after we merge everything ready for 0.3 release, so that there are less conflicting open pull requests.