Experimental support for relative_root_url

[simensen]

From @asm89; references balrog support for $relativeUrl. Idea being that you don't want to have the full site URL in every link.

Refs #47

[gnutix]

@simensen Any news about that ?

[jmikola]

I assume this is only relevant if Sculpin's controller is being served out of a sub-directory? I simply stopped including site_url in my links and have been relying on the relative paths of each content item, which tend to start with a /.

[WyriHaximus]

👍 look good to me, also relative_root_url > root_relative_url because it's explicit about it's purpose.

[davedevelopment]

👍

[simensen]

It is important to note that I changed the title from root_relative_url to relative_root_url in order to make the title reflect the reality of the code that was actually merged.